CA2032587C - Data carrier having a liquid crystal security element - Google Patents
Data carrier having a liquid crystal security elementInfo
- Publication number
- CA2032587C CA2032587C CA002032587A CA2032587A CA2032587C CA 2032587 C CA2032587 C CA 2032587C CA 002032587 A CA002032587 A CA 002032587A CA 2032587 A CA2032587 A CA 2032587A CA 2032587 C CA2032587 C CA 2032587C
- Authority
- CA
- Canada
- Prior art keywords
- liquid crystal
- data carrier
- security element
- carrier
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/30—Identification or security features, e.g. for preventing forgery
- B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
- B42D25/364—Liquid crystals
-
- G—PHYSICS
- G07—CHECKING-DEVICES
- G07F—COIN-FREED OR LIKE APPARATUS
- G07F7/00—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus
- G07F7/08—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means
- G07F7/086—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/30—Identification or security features, e.g. for preventing forgery
- B42D25/355—Security threads
-
- B42D2033/26—
Abstract
A data carrier such as an identity card or a paper of value protected against attempted forgery using color copiers and containing an optically variable security element made of a liquid crystal material. The security element. e.g. a safeguarding thread, has a plastics-like layer made of a liquid crystal polymer which shows a pronounced play of colors at room temperature. The plastics-like properties of liquid crystal polymers permit easy processing into a semifinished product or into the finished product, so that completely different types of security elements can be produced.
Description
1~ 2032~87 A data carrier having a llquld crystal security element The presenl invention relates to data carriers. in particular papers of ~ alue. documents. identity cards or the lil;e. ha~ing ~n optically ~-ariahle security element containing a liquid crystal material. For e~sier rea(i~bil-ity the abbre~,-iation "LC" will be frequently used in the follou-ing for "liquid crystal."
The increasing technical maturity of color (~or iers leads tO copies that are ever more difficult to distinguish from the originals in color.
resolution and quality. To protect data carriers from being forged with the aid of color copiers or scanners. optically ~-ariable elements are being used more and more as security elements. Such elements ha~ e in common that they exhibit different colors or brightnesses depending on the light-ing and viewing conditions. The commonest opticall~ ~ariable elements are diffraction grids. holograms! lnterference coatings. metameric inks and polarizing coatings.
Holograms and grids are based on diffractive effects. Interference coatings usually comprise several superjacent la~v-ers! the la!t er thicknesses being within the size of the wavelength of the light.
Metameric inl;s customarily consist of mixtures of pigments with dif-ferent reflectance bands. This composition causes the metameric inks to change their visual color effect when the type of lighting changes.
Dichroic dyes have the property of absorbing white light in different wave ranges depending on the polarizing direction. The result is a polarization-dependent color effect.
The disadvantage of the known opticall~ variable authenticity fea-tures is that they are t, ery expensive to produce. cannot be processed using conventional production methods or are not fully compatible with other authenticity features or card elements.
- ~ 2032587 The in~-ention is based on the problem of proposing a featur~ effec-tive as copying protection that has effects dependent on the viewing angle! can be produced inexpensk-ely and using con~-entional methods and is compatible or combinable ~vith other features.
This problem is solved by the features stated in the characterizing part of the main claim~ Developments are stated in the dependent and independent claims.
The invention is based on che use of liquid crystal polymers as secu-rity elements. ~fter suitable oriented production these polymers constitute at room temperature a plastics-like solid ~h-ith a pronounced play of col-ors. .~ suitable production method is, for example. ~o doctor the material u~hile still liquid onto a base and subsequently harden it by UV irradia-tion. Suitable liquid crystal polymers are in particular liquid crystal-silicone polymers and cholesteric organopolysiloxanes. Their chemical structure and production are described in the published patent applica-tions EP-A 0 136 501. EP-A 0 060 335 and European patent no. 0 066 13,.
The disclosed content of these publications is expressly referred to.
The use of conventional liquid crystals as securit~ elements is already ~nown and is proposed. for example. in Australian patent no. ~88 652 (Commonwealth). This reference describes a laminated bank note with an intermediate layer in which a security element is embedded in the form of a liquid cry, stal material. The LC material is applied to an inlay by print-ing technology. The liquid crystals are in a liquid state of aggregation.
are embedded in microcapsules closed on all sides and mixed into an ink.
The test for authenticity involves a change of color of the security ele-ment due to a change of temperature.
Despite a structural anisotropy, liquid crystals customarily behave lil;e liquids. which is why it is necessary to enclose these materials in capsules or cavities. This results in complicated production engineering.
~ot onl~ is the encasing of the LC materials elaborate. it is also impos-sible to embed the proposed security elements in films or identity docu-ments in the con~, entional way under the action of pressure and heat ~classical laminating technique) due to the danger of injuring the cavities or capsules. Encased liguid crystals are also unsuitable as security ele--ments on ban~ notes ol papers of ~-alue riith steel intaglio printing since the high pressllre stresses required in this production method lead to destruction of the capsules and ca~-ities.
Howe~-er. after cortesDonding processin,~ uid cryslals can also be present in a solid form and e.Yhibit a high-grade orientation of their molecllles depen(iing on the processing method. making their opt~call~
~-ariable properties stand out to their full e.~tent and in full brillianc~. Jn the inventive LC sy, stems the color p~lrity of the reflected light onl~-rarely e.~iceeds a range of 100 nm. the color change effects upon a change of ~ie~.ving angle ;are ~,-ery pronounced. and the reflected and transmitted light has a pronounced circular polarization. These fully de~-eloped opti-cally variable properties make such LC polymers particularly suitabiP for use as security elements on data carriers. papers of t-alue and identity cards. The plays of color are easily obser~ able e~;en for the la~-man. The ~-a~ elength-selective reflecti~ ity and the polariza~ion effects mal;e the material highly suitable for automated testing. The multiplicity and pro-nounced character of the optical effects mal;es it diffLcult to prepare simulacrum counterfeits. in v irtually all embodiments the LC elements can be additionally employed both as machine-readable authenticity fea-tures and together w-ith other machine features. Due to the IR permeabil-ity of LC polymers the other machine features might also be disposed under the LC polymers.
The solid properties of LC polymers make it considerably easier to produce security elements from them. Firstly. it is unnecessarv to enclose the liquid crystals in a hollow body. Secondly, there is no danger of bursting and of the liquid crystals leal;ing out during following pro-cessing steps and during the lif'e of the data carrier. This makes the production processes and application extremel~. uncomplicated.
The plastics-like properties of liquid crystal polymers allow for easy processing into semifinished products or into the finished product. The starting material is generally present as granular material and can be shaped and processed with the methods and machines known from plastics production. This makes it possible in the field of security technology to produce completely different types of security elements on the basis of L~ polymers and to co~rer different cases of application. ~-Thlls. carriel Uel~S made of tear-resistarlt pLast,^s can l~e t oate(l -~ith a la~-er of LC pol~mers. The resulting w,eb of material can then he cut into narrow webs or threads that can be embedded ~n paper or other sub-stances as safeguarding threads.
.'~lternativel-. multilayer wehs of fi]rn c,ln also be produced that con-.ain an embedded layer made of an LC polymer. Such ~.4ehs an ~)e forrrled as adhesive or transfer bands that are suitable for gluing or s.amping transfer elements onto paper or plastics surfaces.
Finally LC polymers can also be produced as selr-supporting films.
These films can be used. for e.~;ample. as layers of film for m~lltilayer identity cards.
Further advantages and features of the invention can be found in the dependent and independent claims and the follo~ ing e~;emplary embodi-ments and flgures. in which Fig. 1 -shows the spectral transmission and reflection properties of LC polymers from various viewing angles.
Fig. '' shou,-s a bank note with a window safeguarding thread having one or more layers made of LC polymers!
Fig. 3 shows a safeguarding thread having a layer made of an LC
polymer.
Fig. 1 shows a symmetrically constructed safeguarding thread having outside layers made of LC polymers.
Fig. 6 shows a symmetrically constructed safeguarding thread having inside layers made of LC polymers, Figs. 6a, b show a printed. symmetrical .vindo~- safeguarding thread in cross section and from the top, Figs. 7a, b show a printed safeguarding thread having kinetic effects in cross section and from the top, Figs ~a. b sho w an identity cal d ha~ ing a tr~r ;fer element -.~ ith an LC la~ er from the from ~nd in cross secti()n.
F;~JS. ~a. b shou an identitv car d ha~ing a ~ isu~hy unreadable coding co~,-ere(i b~ the se~urit-; element.
Fig. 1~) shows a cross section through a transfer ba-.d.
Fig. 11 shows the transfer of an LC securit v elemen- to a sllbstrate.
Fig. 1~ shows an identity card having a laminated-in layer made of LC polymer.
Fig. 13 shows a test assembly for LC security elemeats.
Figs. ~ show detector assemblies ~or de~ecting LC security elements .
To mal;e it easier to understand the applicat ons and effects of liquid crystal polymers that are discussed in the Figures and e.~emplary embodiments, some important properties of these subs;ances shall be e.~-plained in advance.
LC polymers are a special variant of liquid c.-stals in ~hich the liquid cr!.-stalline state is "frozen" in a pol~-mer rnatri~, so that the optical properties stand out particul&rly clearly. Thus. liquid crystal pol~
mers normally absorb no light; their coloring arises by multiple interfer-ence of light on the individual crvstal planes. The coior effect in incident and transmitted light is accordingly different. The reflected color spec-trum contains only a narrow frequency range about a central wavelength and thus shows a high color saturation. The transmitted spectrum is com-plementary to the reflected one and has a sag in the area about the central wa~-elength.
When LC polymers are used on opaque substrates one obtains a par-ticularly high degree of color purity for all viewing angles if the liquid crystal layer is applied to a black background. The reflected spectrum is then not disturbed by secondary reflections on-the background.
- ~ 2032~87 The lattice ronstants ~f in~ enti~;e oriente~ L-~ polymers can he set.
or defined during syn~hesis. to be in the range of 300 nm to l~000 nm. so that the reflected central wa~,-elength when verticall~ incident is in the near infr ared or the ~ isible range. .~s the viewing angle fla~;tens. the central wa~,elength of the reflection banli shifts in t~ direction of short-er wavelengths. For e.~ample, the perpendicular r eFlected l~avelength is appro~. 20o greater than reflection at ~0 .
Fig. 1 shows spectral reflection R of an LC layer h-ith vertically inci-dent illumination in curve 1 and with a lighting direction of 60 in cur--e ''. For special LC polymers the color effect can accordinglv change from green to ~i-iolet. -ellow to blue. light red to ~reen or. with an IR
!eflection band from black to red. The lattice constan~ and thus the basic color of the liquid crystal polymer depends on the precise chemical struc-ture of the liquid cr,~ stal and can be defined by the synthesis conditions to be in the range between 300 and l.000 nm.
Fig. 2 shows an application of an LC polymel for a window safe-guarding thread. In a banl; note 11 ~-ith a security print 12 a safeguard-ing thread 13 has been embedded during the paper production in such a ~ay that it comes to lie in ~indows 11 on the surface of the paper and is thus visuallv recognizable. Depending on the embodiment. the ~idth of such safeguarding threads fluctuates between 0.5 and a few millimeters.
~ o give the bank note copying protection by optically variable ef-fects, safeguarding thread 13 is designed in such a ~ay that it contains one or more layers made of an LC polymer. ~;ariants for producing and constructing safeguarding threads are shown in Figs. 3 tO ~.
Fig. 3 shows the cross section of a first variant for a safeguarding thread 1 3a. It comprises a plastics carrier 20, for which a polyester film ~ith a typical thickness of 20 to 100 micrometers is preferably used.
Carrier 20 is coated on one side with a several micrometer thick layer 21 made of an LC polymer. To bring out optically the plays of color of the liquid crystals, film 20 is preferably dyed blacl;. The thread is oriented during the paper production in such a way that the liquid crystal layer is present on the visible outer surface.
--- I 2032~87 Fig. I shows a cross section of a further variant of a safeguarding rhread ].3b -Alith a c~mmetrical laver structure. Symmetric.llly constructed safeguarding threads have the advantage that the orientation of the thread need not be heeded when it is embedded in the paper, Thre:3d 13b comprises two carrier films ~0 th.lt ~re bolh coated on one side ~ith la~er 21 of LC polvmers. Carrier films 20 are interconnecte(i with ~l lami-nating agent 2 ~ so as tO give rise to a svmmerrical lavel structur e wil h outside LC la~ ers. T(- increase the wealth of coll)r one can optionally dye carrier webs ~'0 and, or laminating agent ~ with transparent or pigrnent inl;s. A simple solution in terms of production engineering is to d~-e onl,v laminating agent "~, preferably using an opatllle black.
Fig. 5 shows a further v ariant of a svmmetricall~ (~onstructed safe-guarding thread 1 3c in cross section. In contrast to Fig. 3, carrier films _0 now lie on the outer sides of thread 1 3c, thereby protecting inside LC la!,~ers 21 from being damaged. In this variant, preferablv only the laminating agent is colored with a dye, Since outside carrier la,vers 20 must remain transparent the,v are colored either weakly or not at all.
Figs. 6a and 6b show a further variant of a safeguarding thread 13d in cross section (Fig, 6a) and from the top (Fig. 6b). As in Fig. ~. thread i 3d has a svmmetrical la,ver structure comprising two carrier films 20, two LC layers ~'1 and an adhesive layer 2~'. In the course of a production process the thread was joined together from two coated pairs of films 30, 31. Before joining, surface 33 of one of the pairs of films was furnished ~-ith a printed pattern 3~ of black ink, alphanumeric marks being applied in microwriting to the surface of an LC polymer layer by a conventional printing method. A transparent laminating agent 22 was additionally used.
In transmitted light the characters now appear black before the optically ~-ariable colored background of the polymer layer in the window areas of the paper. In incident light, however, only the micro-characters show a change of color.
In another variant of the safeguarding thread of Figs. 6a and 6b characters 34 are applied in green microprint to one of the LC layers ~hile laminating agent 22 is dyed black, Simultaneously the LC material is selected so as to appear green at a certain viewing angle, for example perpendicular to the black background. When the safeguarding thread is viewed at this angle the total surface then appears green. When the viewing angle changes, the color of the LC polymer layer changes. While in the writing the green color remains ~m;n~nt. The result is a safe-guarding thread whose writing is visible only when the thread is tilted.
It is of course also possible to orientate the liquid crystal material by doctoring. This could for example be done by doctoring or rolling the liquid crystal polymer onto the surface of the roller. The liquid crystal polymer is then transferred from the roller to the surface of the data carrier by a printing process.
Figs. 7a and 7b show a further variant 13e in cross section (Fig.
7a) and from the top (Fig. 7b). The safeguarding thread comprises a carrier film 20 and a layer 21 made of LC polymers. The polymer layer was printed with a pattern of different-colored diagonal stripes 40 by a conventional printing method. In the example shown, the special color sequence selected for pattern 40 was red 41, yellow 42, green 43, blue 44, the pattern being repeated any number of times over the length of the thread. When this safeguarding thread 13e is viewed, colored surface areas 40 appear through the LC layer with different color effects each time. The color spectrum of the individual areas is composed of the reflection bands of the printed dyes. In addition, the colors of the liquid crystal layer are admixed additively. Due to the angle-dependent reflection characteristics of LC polymers, the colored stripes with the arrangement shown can create the illusion of a colored stripe moving along the thread when the thread is tilted, if the colors of the LC
polymer are suitably coordinated. As in Fig. 5, this variant can also be expanded into a safeguarding thread having a symmetrical layer structure.
The variants shown in Figs. 3 to 7 can be varied in manifold ways depending on the desired appearance. The optically variable effects of 3 ' `'' 8a 2032S87 LC polymers can be combined by dyeing any desired layers with "classical"
inks, using et her transparent dyes or pigment dyes. The dyes themselves can be introduced into any layer (including the LC layer, but then only in a low concentration) of the safeguarding thread and/or applied as a printed pattern to any layer of the thread.
The ways of dyeing stated in the description of the figures are only intended by way of a proposal; the stated colors can be replaced at will by any other dyes. These possibilities of combination result in an enormous multiplicity of possible color variations, color illusions and kinetic effects.
The variants of safeguarding threads shown in Figs. 3 to 7 can all be A
pro(luced oll the basis of one semifinished pr od~lct. The semifinished pJ od-uct is prodl~c~cl bv coatinS~ a l,veb of film ~0 made of a carrier material such as polyesteI plastics -~4ith a lay~ 1 of LC polymers. Depending on the coh~r design Or the safeguar~ing thread~ orle llses printed. transp,lrent or dved c~rrier filrns. The thicl;ness of the ~.~eh of film is preferably in the range of less than one tenth of a millimeter: ~or the LC c()ating a film thicl~ness of ~ppro.~i. 10 micrometers is usl1allv ,ufficient. For m~nu-facturing reasorls the tvpical web widths of the semifinished prodllct are in the range of one meter.
Printed safeguarding threads are prodllced by printing the desired patterns or characters on the carrier web and or the LC laver bv a suit-able production method on known printing machines. ~,Ililtilaver, especiallv symmetricallv constructed safeguarding threads are produced bv placing the coated and possibl-- printed webs of film one ~Ipon the other ~nd con-necting them with a laminating agent.
Only when the webs have the desired layer structure are they cut into the threads on know-n cutting apparatus. The flnal thread ~.4idth is in the range of 0.5 to 5.0 rnm depending on the desired application. The resulting threads are suitable in particular for being embedded in paper but can also be embedded between the plastics lavers of an identity card.
Another class of security elements are transfer elements. which are frequentlv applied to credit cards, identity cards! banl; notes, papers of value and the like tO protect them from forgerv and in particular from being multiplied by copving. For these purposes one can also use security elements based on LC polymers due to their opticallv variable properties.
~he transfer elements are transferred to the surface of the objects to be protected from carrier bands by the transfer method.
Figs. 8a and 8b show an identity card 70 with a symbolically repre-sented data record ~9 and a transfer security element 51 in a front view and a sectional view. Security element 51 contains a layer made of an LC
polymer, which is why it has the plays of color typical of these materials.
Transfer elements customarily comprise several layers. Fig. 8b shows a section through the identity card along the line 1.1. In the Figure the height of the elements is highl~ e~;aggerated. it is usually on]v a fe h tenths of a micrometer. Substrate ~3 bears successivelv an adhesive laver .~. a lavel of protf~ctive lacquer 5~. an LC layer .~6 and final outside laver of l)rotecti~-e lacquer .~,. This securitv element. shown here in ery simple embodiment. can be v~rie(i in manv different ~hays.
The ~ossibilities for the color desi~n of L.C elements al e analogou~; to those for safeguardin~, threads. If one desires clearly (visuallv) r ecogniz-able plavs of color one preferably dyes the bacl;ground black. To mi,Y a color into the reflected spectrum one applied element .51 to a print.ed bachground 60. as shown in Fig. 8a. The printed pat;ern can ~ aried in manv wavs: a simple design is a monochrome background: a polvchrome printed background with contrasting alphanumeric characters or patterns such as brightly colored diagonal stripes. interpenetrating colored circles.
etc., has an impro~!ed optical effect. Particularly interesting effects are obtained if bacl;ground 60 contains a black and white or colored photo-graph, a signature and the lil~e.
Similar color effects to the printing of the background can be ob-tained by dyeing, printing or writing on suitable optically effective lavers of the transfer element. that do not change during transfer.
As ~-ill be e~;plained below. the transfer principle makes it possible tO
give the optical element any desired outer contour. The coat of arms shape 61 shown in Fig. 8 is therefore representative of a stripe, a seal. a company logo! an alphanumeric character, numbering, a guilloche pattern, etc. The shape of outline 61 gives the optically variable element an individual character.
Figs. 9a and 9b show a front view and a sectional view of an appli-cation variant in which card data are both inconspicuousl,v camouflaged and protected from falsification by an LC element. LC polymers with readily visible plays of color are usually transparent in the infrared and can thus be easily combined with codings readable in the infrared range.
In a first printing process a coding 72 was applied for this purpose to the surface of a card 70 with an IR-absorbent ink 71. In the next step this IR coding 72 was overprinted with an IR-transparent ink , 3 that is ~ opaque in the visible spectral range. In the last step an LC security ele-Il 2032587 ment , ~ was then sealed onto opaque inl; , 3 in this al ea For manufacturing r easons one prefers the tr;lnsfer principle forapplving security elements made of LC polvmers to the surface of a sllb-strate. In a first method step a transfer band is ~rodllced. and in a ~c-ond method step the security element is detached from the transfer band and connected with the substrate.
Fig. 10 shows the structure of a transfer band 100 in Cl'OSS section.
as is suitable for applying security elements with an LC laver tO a sub-strate surface. A carrier film 101 bears successi~relv a wax la-er 102, a layer of prolective lacquer 103. a layer made of an LC polymer 101. a color layer 105 and a heat-sealing layer 106. The carrier film is pref-erably made of a tear-resistant plastics polvester with a thickness in the range of less than one tenth of a millimeter. The other layers of a trans-fer band customarily have a thickness of a few micrometers to a few tenths of a micrometer. Layers 103 to 106 located on the wax layer form the subsequent security element. To obtain color effects one can dye or print the transfer band in various layers during its production.
To apply the security element to the substrate one places transfer band 100 with heat-sealing layer 106 on substrate l l l, as shown in Fig.
11, and presses them. The pressing is performed with a heated transfer die 11 2 or alternatively with a transfer roll. Under the action of pressure and heat the heat-sealing layer bonds with the substrate. Simultaneously, separation layer 102 melts. allowing for carrier material 101 to be -re-moved. The security element is bonded with the substrate only in the surface areas in which the separation layer has become liquid, i.e. only in the surface areas heated by the transfer die. In the other surface areas the layer structure and the carrier material remain firmly inter-connected. When the carrier film is removed from the substrate the laver structure tears along contour edges 11 3 of the transfer die, whereby contour 11 3 of the transferred security element always corresponds to the contour of the press die. In this way one can also realize complicated contour structures such as company logos, block letters and the like. The process of heat-sealing as such is known and is described, for e~ample, in German laid-open print no. 33 08 831.
LC pol~mers can also be made into films. In this form thev are sllit-able in partic~llar as large-sulface or all-over securit~ elements for multi-lay~r identitv cards.
Figs. l')a an~ l''b sho~- b~v wa~, ot e~ample a larninated idenritv c ard 1~0 comprising a paper inlay 1"1 and two outside rhermoplastic cover films 1 '''' and 1''3. The lavers aI e pressed under the action of ~ressur e and heat into a compact identit~ card. The card information is custorTI-arily printed on the inla~ that. in the e.~ample shown. has a picture of the o~-ner 1~. card data 1~ and a companv logo 1~'6. ~he protection from forgerv ~-as increased bv integrating a film made of l C pol~mer 1", in~o the card structure bet~heen the inlay and the upper ~over film in the left half of the card. The plays of color of the liquid crystal film can be obser~ied through the transparent cover film. whereby color-printed com-pany logo 1'~6 provides additional color effects.
Some LC compounds crosslink under the action of high-energy ~e g.
U~;) radiation and only then form a chemically stable film. T:ne.yposed, i.e.
unhardened. areas can be removed with solvents. In analogy to the kno ~n photographic methods of semiconductor and printing plate production one can thus expose a predefined surface of an LC film through a mask and then remove the coating chemically in the unexposed areas, thereby cre-ating patterns, letters. numbers, etc.
It is of course also possible to cover the entire card surface -~-ith the liquid crystal polymer film. As an alternative to integrating a film into the card structure one might prefer to transfer the liquid crystal element to the inlay before lamination by the transfer principle. A further variant is to replace one or both cover films 122, 123 as a whole by an LC film in the usual structure of laminated cards.
Films made of LC materials are suitable as large-surface or all-over security elements. Such films are preferably made from a liquid crystal substance. To obtain a film suitable for security purposes one processes the LC substance on a roller frame. The orientation of the liquid crystal molecules necessary for the optical effects is effected by shearing forces that occur during rolling. The resulting film material is suitable in particular for the production of identity cards but can also be used for _ 1~ 2032587 other authenticity marl;s. such as safeguarding threa~s.
For automatic testing of authenticit-- marl;s based on the inventive liquid crvstal pol! mers. their polarization properties and their ~avelerlgth selectivity are particularlv suitable. The reflected light is initially con-stricted spectrally to a range about the central wavelength. and llnpolar-ized light is also brol~en down in liquid crystal polymers into right- and left-handed components. Depending on the chemical composition of the polymer only one of the components is reflected, while the complementary component is transmitted.
One possibilit~, of automatic testing shall be shown in the following with reference to an LC polymer film located on a black. completely absorbent carrier 128. As shown in Fig. 13, element 130 is illuminated at a predetermined angle with an unpolarized light beam 131. for e~ample an incandescent lamp 129 . After reflection. Iight beam t 32 hits detector system 133 shown in Fig. 14 used for detecting the spectral filtering and the circular polarization.
The structure of detector system 133 is shown in Fig. 1~L. Within detecror system 133 reflected beam 132 initially passes through a color filter 141, that onlv lets through light of the expected central wave-length. The light beam then hits a lambda, 4 plate 11~ that converts the circular polarization into a linear polarization. The light then hits a 1:1 beam splitter 113. from where two partial beams 144, 145 reach two detectors 146, 147 with polarizing filters 148,- 149 disposed therebefore.
Planes of polarization 150! 151 of the two filters are perpendicular to each other, while being aligned at 45 with the two optical axes of the lambda/ 4 plate.
The automatic authenticity testing is based on an analysis of the two detector signals. The mode of functioning of the detector system is shown in the following with reference to several cases.
A) Authentic element The reflected light passes the color filter without hindrance. In the lambda/4 plate a linear, either horizontal or vertical, polarization is pro--- ,~ 2032587 duced from the circular polarization. The linear polarization callses one ofdetectors l 16, 1~7 receive the full intensity while the second detector receives no light.
B~ Forged element with unpolarized reflection The spectrally correct but unpolarized reflected light has no pre-ferred polarizing direction even after passing the lambdai4 plate. Each detector receives 50% of the reflected light.
C) Forged element with spectral error The reflected light is absorbed in color filter 1~'' and accordingly neither of the detectors receives a signal.
D) Forged element with linear polarization The ~5' arrangement of the lambda/4 plate and the two polarizers causes both detectors to receive the same signal regardless of the orig-inal polarizing direction of the reflected light.
To increase the error significance one can also emplo!Y several detec-tor systems for testing one element, the systems being disposed for ex-ample at different angles and accordingly reacting to different central wavelengths .
It is clear to the expert that the detector system can be realized in many different ways. Fig. 15 shows, as an easy-to-service alternative, an arrangement using optical fibers. The basis of the optical arrangement is again Fig. 13. In detector system 133, reflected light beam 132 initially passes through a color filter 161 to check the central wavelength. In following lambda/4 plate 162 the circular polarization is converted into a linear one. An input coupling optical system 153 couples light beam 132 into a waveguide system 154, known beam separators separate the beam into equivalent partial bundles. At the end of each partial bundle there is a polarizer-detector pair 155/156 and 157/158 for the two different polar-izing directions.
~ 2032~87 If the light has the corr~ct wavelength and polarization one of the two detectors 156/15~S receives (in the case of lossfree optics) 5(1,'o of the input intensity. the second receives no light. In the case of a forged ele-ment reflecting unpolarized light. each of the detectors receives 50% of the input intensity. In this wav one can distingl]ish forgery from the original .
The increasing technical maturity of color (~or iers leads tO copies that are ever more difficult to distinguish from the originals in color.
resolution and quality. To protect data carriers from being forged with the aid of color copiers or scanners. optically ~-ariable elements are being used more and more as security elements. Such elements ha~ e in common that they exhibit different colors or brightnesses depending on the light-ing and viewing conditions. The commonest opticall~ ~ariable elements are diffraction grids. holograms! lnterference coatings. metameric inks and polarizing coatings.
Holograms and grids are based on diffractive effects. Interference coatings usually comprise several superjacent la~v-ers! the la!t er thicknesses being within the size of the wavelength of the light.
Metameric inl;s customarily consist of mixtures of pigments with dif-ferent reflectance bands. This composition causes the metameric inks to change their visual color effect when the type of lighting changes.
Dichroic dyes have the property of absorbing white light in different wave ranges depending on the polarizing direction. The result is a polarization-dependent color effect.
The disadvantage of the known opticall~ variable authenticity fea-tures is that they are t, ery expensive to produce. cannot be processed using conventional production methods or are not fully compatible with other authenticity features or card elements.
- ~ 2032587 The in~-ention is based on the problem of proposing a featur~ effec-tive as copying protection that has effects dependent on the viewing angle! can be produced inexpensk-ely and using con~-entional methods and is compatible or combinable ~vith other features.
This problem is solved by the features stated in the characterizing part of the main claim~ Developments are stated in the dependent and independent claims.
The invention is based on che use of liquid crystal polymers as secu-rity elements. ~fter suitable oriented production these polymers constitute at room temperature a plastics-like solid ~h-ith a pronounced play of col-ors. .~ suitable production method is, for example. ~o doctor the material u~hile still liquid onto a base and subsequently harden it by UV irradia-tion. Suitable liquid crystal polymers are in particular liquid crystal-silicone polymers and cholesteric organopolysiloxanes. Their chemical structure and production are described in the published patent applica-tions EP-A 0 136 501. EP-A 0 060 335 and European patent no. 0 066 13,.
The disclosed content of these publications is expressly referred to.
The use of conventional liquid crystals as securit~ elements is already ~nown and is proposed. for example. in Australian patent no. ~88 652 (Commonwealth). This reference describes a laminated bank note with an intermediate layer in which a security element is embedded in the form of a liquid cry, stal material. The LC material is applied to an inlay by print-ing technology. The liquid crystals are in a liquid state of aggregation.
are embedded in microcapsules closed on all sides and mixed into an ink.
The test for authenticity involves a change of color of the security ele-ment due to a change of temperature.
Despite a structural anisotropy, liquid crystals customarily behave lil;e liquids. which is why it is necessary to enclose these materials in capsules or cavities. This results in complicated production engineering.
~ot onl~ is the encasing of the LC materials elaborate. it is also impos-sible to embed the proposed security elements in films or identity docu-ments in the con~, entional way under the action of pressure and heat ~classical laminating technique) due to the danger of injuring the cavities or capsules. Encased liguid crystals are also unsuitable as security ele--ments on ban~ notes ol papers of ~-alue riith steel intaglio printing since the high pressllre stresses required in this production method lead to destruction of the capsules and ca~-ities.
Howe~-er. after cortesDonding processin,~ uid cryslals can also be present in a solid form and e.Yhibit a high-grade orientation of their molecllles depen(iing on the processing method. making their opt~call~
~-ariable properties stand out to their full e.~tent and in full brillianc~. Jn the inventive LC sy, stems the color p~lrity of the reflected light onl~-rarely e.~iceeds a range of 100 nm. the color change effects upon a change of ~ie~.ving angle ;are ~,-ery pronounced. and the reflected and transmitted light has a pronounced circular polarization. These fully de~-eloped opti-cally variable properties make such LC polymers particularly suitabiP for use as security elements on data carriers. papers of t-alue and identity cards. The plays of color are easily obser~ able e~;en for the la~-man. The ~-a~ elength-selective reflecti~ ity and the polariza~ion effects mal;e the material highly suitable for automated testing. The multiplicity and pro-nounced character of the optical effects mal;es it diffLcult to prepare simulacrum counterfeits. in v irtually all embodiments the LC elements can be additionally employed both as machine-readable authenticity fea-tures and together w-ith other machine features. Due to the IR permeabil-ity of LC polymers the other machine features might also be disposed under the LC polymers.
The solid properties of LC polymers make it considerably easier to produce security elements from them. Firstly. it is unnecessarv to enclose the liquid crystals in a hollow body. Secondly, there is no danger of bursting and of the liquid crystals leal;ing out during following pro-cessing steps and during the lif'e of the data carrier. This makes the production processes and application extremel~. uncomplicated.
The plastics-like properties of liquid crystal polymers allow for easy processing into semifinished products or into the finished product. The starting material is generally present as granular material and can be shaped and processed with the methods and machines known from plastics production. This makes it possible in the field of security technology to produce completely different types of security elements on the basis of L~ polymers and to co~rer different cases of application. ~-Thlls. carriel Uel~S made of tear-resistarlt pLast,^s can l~e t oate(l -~ith a la~-er of LC pol~mers. The resulting w,eb of material can then he cut into narrow webs or threads that can be embedded ~n paper or other sub-stances as safeguarding threads.
.'~lternativel-. multilayer wehs of fi]rn c,ln also be produced that con-.ain an embedded layer made of an LC polymer. Such ~.4ehs an ~)e forrrled as adhesive or transfer bands that are suitable for gluing or s.amping transfer elements onto paper or plastics surfaces.
Finally LC polymers can also be produced as selr-supporting films.
These films can be used. for e.~;ample. as layers of film for m~lltilayer identity cards.
Further advantages and features of the invention can be found in the dependent and independent claims and the follo~ ing e~;emplary embodi-ments and flgures. in which Fig. 1 -shows the spectral transmission and reflection properties of LC polymers from various viewing angles.
Fig. '' shou,-s a bank note with a window safeguarding thread having one or more layers made of LC polymers!
Fig. 3 shows a safeguarding thread having a layer made of an LC
polymer.
Fig. 1 shows a symmetrically constructed safeguarding thread having outside layers made of LC polymers.
Fig. 6 shows a symmetrically constructed safeguarding thread having inside layers made of LC polymers, Figs. 6a, b show a printed. symmetrical .vindo~- safeguarding thread in cross section and from the top, Figs. 7a, b show a printed safeguarding thread having kinetic effects in cross section and from the top, Figs ~a. b sho w an identity cal d ha~ ing a tr~r ;fer element -.~ ith an LC la~ er from the from ~nd in cross secti()n.
F;~JS. ~a. b shou an identitv car d ha~ing a ~ isu~hy unreadable coding co~,-ere(i b~ the se~urit-; element.
Fig. 1~) shows a cross section through a transfer ba-.d.
Fig. 11 shows the transfer of an LC securit v elemen- to a sllbstrate.
Fig. 1~ shows an identity card having a laminated-in layer made of LC polymer.
Fig. 13 shows a test assembly for LC security elemeats.
Figs. ~ show detector assemblies ~or de~ecting LC security elements .
To mal;e it easier to understand the applicat ons and effects of liquid crystal polymers that are discussed in the Figures and e.~emplary embodiments, some important properties of these subs;ances shall be e.~-plained in advance.
LC polymers are a special variant of liquid c.-stals in ~hich the liquid cr!.-stalline state is "frozen" in a pol~-mer rnatri~, so that the optical properties stand out particul&rly clearly. Thus. liquid crystal pol~
mers normally absorb no light; their coloring arises by multiple interfer-ence of light on the individual crvstal planes. The coior effect in incident and transmitted light is accordingly different. The reflected color spec-trum contains only a narrow frequency range about a central wavelength and thus shows a high color saturation. The transmitted spectrum is com-plementary to the reflected one and has a sag in the area about the central wa~-elength.
When LC polymers are used on opaque substrates one obtains a par-ticularly high degree of color purity for all viewing angles if the liquid crystal layer is applied to a black background. The reflected spectrum is then not disturbed by secondary reflections on-the background.
- ~ 2032~87 The lattice ronstants ~f in~ enti~;e oriente~ L-~ polymers can he set.
or defined during syn~hesis. to be in the range of 300 nm to l~000 nm. so that the reflected central wa~,-elength when verticall~ incident is in the near infr ared or the ~ isible range. .~s the viewing angle fla~;tens. the central wa~,elength of the reflection banli shifts in t~ direction of short-er wavelengths. For e.~ample, the perpendicular r eFlected l~avelength is appro~. 20o greater than reflection at ~0 .
Fig. 1 shows spectral reflection R of an LC layer h-ith vertically inci-dent illumination in curve 1 and with a lighting direction of 60 in cur--e ''. For special LC polymers the color effect can accordinglv change from green to ~i-iolet. -ellow to blue. light red to ~reen or. with an IR
!eflection band from black to red. The lattice constan~ and thus the basic color of the liquid crystal polymer depends on the precise chemical struc-ture of the liquid cr,~ stal and can be defined by the synthesis conditions to be in the range between 300 and l.000 nm.
Fig. 2 shows an application of an LC polymel for a window safe-guarding thread. In a banl; note 11 ~-ith a security print 12 a safeguard-ing thread 13 has been embedded during the paper production in such a ~ay that it comes to lie in ~indows 11 on the surface of the paper and is thus visuallv recognizable. Depending on the embodiment. the ~idth of such safeguarding threads fluctuates between 0.5 and a few millimeters.
~ o give the bank note copying protection by optically variable ef-fects, safeguarding thread 13 is designed in such a ~ay that it contains one or more layers made of an LC polymer. ~;ariants for producing and constructing safeguarding threads are shown in Figs. 3 tO ~.
Fig. 3 shows the cross section of a first variant for a safeguarding thread 1 3a. It comprises a plastics carrier 20, for which a polyester film ~ith a typical thickness of 20 to 100 micrometers is preferably used.
Carrier 20 is coated on one side with a several micrometer thick layer 21 made of an LC polymer. To bring out optically the plays of color of the liquid crystals, film 20 is preferably dyed blacl;. The thread is oriented during the paper production in such a way that the liquid crystal layer is present on the visible outer surface.
--- I 2032~87 Fig. I shows a cross section of a further variant of a safeguarding rhread ].3b -Alith a c~mmetrical laver structure. Symmetric.llly constructed safeguarding threads have the advantage that the orientation of the thread need not be heeded when it is embedded in the paper, Thre:3d 13b comprises two carrier films ~0 th.lt ~re bolh coated on one side ~ith la~er 21 of LC polvmers. Carrier films 20 are interconnecte(i with ~l lami-nating agent 2 ~ so as tO give rise to a svmmerrical lavel structur e wil h outside LC la~ ers. T(- increase the wealth of coll)r one can optionally dye carrier webs ~'0 and, or laminating agent ~ with transparent or pigrnent inl;s. A simple solution in terms of production engineering is to d~-e onl,v laminating agent "~, preferably using an opatllle black.
Fig. 5 shows a further v ariant of a svmmetricall~ (~onstructed safe-guarding thread 1 3c in cross section. In contrast to Fig. 3, carrier films _0 now lie on the outer sides of thread 1 3c, thereby protecting inside LC la!,~ers 21 from being damaged. In this variant, preferablv only the laminating agent is colored with a dye, Since outside carrier la,vers 20 must remain transparent the,v are colored either weakly or not at all.
Figs. 6a and 6b show a further variant of a safeguarding thread 13d in cross section (Fig, 6a) and from the top (Fig. 6b). As in Fig. ~. thread i 3d has a svmmetrical la,ver structure comprising two carrier films 20, two LC layers ~'1 and an adhesive layer 2~'. In the course of a production process the thread was joined together from two coated pairs of films 30, 31. Before joining, surface 33 of one of the pairs of films was furnished ~-ith a printed pattern 3~ of black ink, alphanumeric marks being applied in microwriting to the surface of an LC polymer layer by a conventional printing method. A transparent laminating agent 22 was additionally used.
In transmitted light the characters now appear black before the optically ~-ariable colored background of the polymer layer in the window areas of the paper. In incident light, however, only the micro-characters show a change of color.
In another variant of the safeguarding thread of Figs. 6a and 6b characters 34 are applied in green microprint to one of the LC layers ~hile laminating agent 22 is dyed black, Simultaneously the LC material is selected so as to appear green at a certain viewing angle, for example perpendicular to the black background. When the safeguarding thread is viewed at this angle the total surface then appears green. When the viewing angle changes, the color of the LC polymer layer changes. While in the writing the green color remains ~m;n~nt. The result is a safe-guarding thread whose writing is visible only when the thread is tilted.
It is of course also possible to orientate the liquid crystal material by doctoring. This could for example be done by doctoring or rolling the liquid crystal polymer onto the surface of the roller. The liquid crystal polymer is then transferred from the roller to the surface of the data carrier by a printing process.
Figs. 7a and 7b show a further variant 13e in cross section (Fig.
7a) and from the top (Fig. 7b). The safeguarding thread comprises a carrier film 20 and a layer 21 made of LC polymers. The polymer layer was printed with a pattern of different-colored diagonal stripes 40 by a conventional printing method. In the example shown, the special color sequence selected for pattern 40 was red 41, yellow 42, green 43, blue 44, the pattern being repeated any number of times over the length of the thread. When this safeguarding thread 13e is viewed, colored surface areas 40 appear through the LC layer with different color effects each time. The color spectrum of the individual areas is composed of the reflection bands of the printed dyes. In addition, the colors of the liquid crystal layer are admixed additively. Due to the angle-dependent reflection characteristics of LC polymers, the colored stripes with the arrangement shown can create the illusion of a colored stripe moving along the thread when the thread is tilted, if the colors of the LC
polymer are suitably coordinated. As in Fig. 5, this variant can also be expanded into a safeguarding thread having a symmetrical layer structure.
The variants shown in Figs. 3 to 7 can be varied in manifold ways depending on the desired appearance. The optically variable effects of 3 ' `'' 8a 2032S87 LC polymers can be combined by dyeing any desired layers with "classical"
inks, using et her transparent dyes or pigment dyes. The dyes themselves can be introduced into any layer (including the LC layer, but then only in a low concentration) of the safeguarding thread and/or applied as a printed pattern to any layer of the thread.
The ways of dyeing stated in the description of the figures are only intended by way of a proposal; the stated colors can be replaced at will by any other dyes. These possibilities of combination result in an enormous multiplicity of possible color variations, color illusions and kinetic effects.
The variants of safeguarding threads shown in Figs. 3 to 7 can all be A
pro(luced oll the basis of one semifinished pr od~lct. The semifinished pJ od-uct is prodl~c~cl bv coatinS~ a l,veb of film ~0 made of a carrier material such as polyesteI plastics -~4ith a lay~ 1 of LC polymers. Depending on the coh~r design Or the safeguar~ing thread~ orle llses printed. transp,lrent or dved c~rrier filrns. The thicl;ness of the ~.~eh of film is preferably in the range of less than one tenth of a millimeter: ~or the LC c()ating a film thicl~ness of ~ppro.~i. 10 micrometers is usl1allv ,ufficient. For m~nu-facturing reasorls the tvpical web widths of the semifinished prodllct are in the range of one meter.
Printed safeguarding threads are prodllced by printing the desired patterns or characters on the carrier web and or the LC laver bv a suit-able production method on known printing machines. ~,Ililtilaver, especiallv symmetricallv constructed safeguarding threads are produced bv placing the coated and possibl-- printed webs of film one ~Ipon the other ~nd con-necting them with a laminating agent.
Only when the webs have the desired layer structure are they cut into the threads on know-n cutting apparatus. The flnal thread ~.4idth is in the range of 0.5 to 5.0 rnm depending on the desired application. The resulting threads are suitable in particular for being embedded in paper but can also be embedded between the plastics lavers of an identity card.
Another class of security elements are transfer elements. which are frequentlv applied to credit cards, identity cards! banl; notes, papers of value and the like tO protect them from forgerv and in particular from being multiplied by copving. For these purposes one can also use security elements based on LC polymers due to their opticallv variable properties.
~he transfer elements are transferred to the surface of the objects to be protected from carrier bands by the transfer method.
Figs. 8a and 8b show an identity card 70 with a symbolically repre-sented data record ~9 and a transfer security element 51 in a front view and a sectional view. Security element 51 contains a layer made of an LC
polymer, which is why it has the plays of color typical of these materials.
Transfer elements customarily comprise several layers. Fig. 8b shows a section through the identity card along the line 1.1. In the Figure the height of the elements is highl~ e~;aggerated. it is usually on]v a fe h tenths of a micrometer. Substrate ~3 bears successivelv an adhesive laver .~. a lavel of protf~ctive lacquer 5~. an LC layer .~6 and final outside laver of l)rotecti~-e lacquer .~,. This securitv element. shown here in ery simple embodiment. can be v~rie(i in manv different ~hays.
The ~ossibilities for the color desi~n of L.C elements al e analogou~; to those for safeguardin~, threads. If one desires clearly (visuallv) r ecogniz-able plavs of color one preferably dyes the bacl;ground black. To mi,Y a color into the reflected spectrum one applied element .51 to a print.ed bachground 60. as shown in Fig. 8a. The printed pat;ern can ~ aried in manv wavs: a simple design is a monochrome background: a polvchrome printed background with contrasting alphanumeric characters or patterns such as brightly colored diagonal stripes. interpenetrating colored circles.
etc., has an impro~!ed optical effect. Particularly interesting effects are obtained if bacl;ground 60 contains a black and white or colored photo-graph, a signature and the lil~e.
Similar color effects to the printing of the background can be ob-tained by dyeing, printing or writing on suitable optically effective lavers of the transfer element. that do not change during transfer.
As ~-ill be e~;plained below. the transfer principle makes it possible tO
give the optical element any desired outer contour. The coat of arms shape 61 shown in Fig. 8 is therefore representative of a stripe, a seal. a company logo! an alphanumeric character, numbering, a guilloche pattern, etc. The shape of outline 61 gives the optically variable element an individual character.
Figs. 9a and 9b show a front view and a sectional view of an appli-cation variant in which card data are both inconspicuousl,v camouflaged and protected from falsification by an LC element. LC polymers with readily visible plays of color are usually transparent in the infrared and can thus be easily combined with codings readable in the infrared range.
In a first printing process a coding 72 was applied for this purpose to the surface of a card 70 with an IR-absorbent ink 71. In the next step this IR coding 72 was overprinted with an IR-transparent ink , 3 that is ~ opaque in the visible spectral range. In the last step an LC security ele-Il 2032587 ment , ~ was then sealed onto opaque inl; , 3 in this al ea For manufacturing r easons one prefers the tr;lnsfer principle forapplving security elements made of LC polvmers to the surface of a sllb-strate. In a first method step a transfer band is ~rodllced. and in a ~c-ond method step the security element is detached from the transfer band and connected with the substrate.
Fig. 10 shows the structure of a transfer band 100 in Cl'OSS section.
as is suitable for applying security elements with an LC laver tO a sub-strate surface. A carrier film 101 bears successi~relv a wax la-er 102, a layer of prolective lacquer 103. a layer made of an LC polymer 101. a color layer 105 and a heat-sealing layer 106. The carrier film is pref-erably made of a tear-resistant plastics polvester with a thickness in the range of less than one tenth of a millimeter. The other layers of a trans-fer band customarily have a thickness of a few micrometers to a few tenths of a micrometer. Layers 103 to 106 located on the wax layer form the subsequent security element. To obtain color effects one can dye or print the transfer band in various layers during its production.
To apply the security element to the substrate one places transfer band 100 with heat-sealing layer 106 on substrate l l l, as shown in Fig.
11, and presses them. The pressing is performed with a heated transfer die 11 2 or alternatively with a transfer roll. Under the action of pressure and heat the heat-sealing layer bonds with the substrate. Simultaneously, separation layer 102 melts. allowing for carrier material 101 to be -re-moved. The security element is bonded with the substrate only in the surface areas in which the separation layer has become liquid, i.e. only in the surface areas heated by the transfer die. In the other surface areas the layer structure and the carrier material remain firmly inter-connected. When the carrier film is removed from the substrate the laver structure tears along contour edges 11 3 of the transfer die, whereby contour 11 3 of the transferred security element always corresponds to the contour of the press die. In this way one can also realize complicated contour structures such as company logos, block letters and the like. The process of heat-sealing as such is known and is described, for e~ample, in German laid-open print no. 33 08 831.
LC pol~mers can also be made into films. In this form thev are sllit-able in partic~llar as large-sulface or all-over securit~ elements for multi-lay~r identitv cards.
Figs. l')a an~ l''b sho~- b~v wa~, ot e~ample a larninated idenritv c ard 1~0 comprising a paper inlay 1"1 and two outside rhermoplastic cover films 1 '''' and 1''3. The lavers aI e pressed under the action of ~ressur e and heat into a compact identit~ card. The card information is custorTI-arily printed on the inla~ that. in the e.~ample shown. has a picture of the o~-ner 1~. card data 1~ and a companv logo 1~'6. ~he protection from forgerv ~-as increased bv integrating a film made of l C pol~mer 1", in~o the card structure bet~heen the inlay and the upper ~over film in the left half of the card. The plays of color of the liquid crystal film can be obser~ied through the transparent cover film. whereby color-printed com-pany logo 1'~6 provides additional color effects.
Some LC compounds crosslink under the action of high-energy ~e g.
U~;) radiation and only then form a chemically stable film. T:ne.yposed, i.e.
unhardened. areas can be removed with solvents. In analogy to the kno ~n photographic methods of semiconductor and printing plate production one can thus expose a predefined surface of an LC film through a mask and then remove the coating chemically in the unexposed areas, thereby cre-ating patterns, letters. numbers, etc.
It is of course also possible to cover the entire card surface -~-ith the liquid crystal polymer film. As an alternative to integrating a film into the card structure one might prefer to transfer the liquid crystal element to the inlay before lamination by the transfer principle. A further variant is to replace one or both cover films 122, 123 as a whole by an LC film in the usual structure of laminated cards.
Films made of LC materials are suitable as large-surface or all-over security elements. Such films are preferably made from a liquid crystal substance. To obtain a film suitable for security purposes one processes the LC substance on a roller frame. The orientation of the liquid crystal molecules necessary for the optical effects is effected by shearing forces that occur during rolling. The resulting film material is suitable in particular for the production of identity cards but can also be used for _ 1~ 2032587 other authenticity marl;s. such as safeguarding threa~s.
For automatic testing of authenticit-- marl;s based on the inventive liquid crvstal pol! mers. their polarization properties and their ~avelerlgth selectivity are particularlv suitable. The reflected light is initially con-stricted spectrally to a range about the central wavelength. and llnpolar-ized light is also brol~en down in liquid crystal polymers into right- and left-handed components. Depending on the chemical composition of the polymer only one of the components is reflected, while the complementary component is transmitted.
One possibilit~, of automatic testing shall be shown in the following with reference to an LC polymer film located on a black. completely absorbent carrier 128. As shown in Fig. 13, element 130 is illuminated at a predetermined angle with an unpolarized light beam 131. for e~ample an incandescent lamp 129 . After reflection. Iight beam t 32 hits detector system 133 shown in Fig. 14 used for detecting the spectral filtering and the circular polarization.
The structure of detector system 133 is shown in Fig. 1~L. Within detecror system 133 reflected beam 132 initially passes through a color filter 141, that onlv lets through light of the expected central wave-length. The light beam then hits a lambda, 4 plate 11~ that converts the circular polarization into a linear polarization. The light then hits a 1:1 beam splitter 113. from where two partial beams 144, 145 reach two detectors 146, 147 with polarizing filters 148,- 149 disposed therebefore.
Planes of polarization 150! 151 of the two filters are perpendicular to each other, while being aligned at 45 with the two optical axes of the lambda/ 4 plate.
The automatic authenticity testing is based on an analysis of the two detector signals. The mode of functioning of the detector system is shown in the following with reference to several cases.
A) Authentic element The reflected light passes the color filter without hindrance. In the lambda/4 plate a linear, either horizontal or vertical, polarization is pro--- ,~ 2032587 duced from the circular polarization. The linear polarization callses one ofdetectors l 16, 1~7 receive the full intensity while the second detector receives no light.
B~ Forged element with unpolarized reflection The spectrally correct but unpolarized reflected light has no pre-ferred polarizing direction even after passing the lambdai4 plate. Each detector receives 50% of the reflected light.
C) Forged element with spectral error The reflected light is absorbed in color filter 1~'' and accordingly neither of the detectors receives a signal.
D) Forged element with linear polarization The ~5' arrangement of the lambda/4 plate and the two polarizers causes both detectors to receive the same signal regardless of the orig-inal polarizing direction of the reflected light.
To increase the error significance one can also emplo!Y several detec-tor systems for testing one element, the systems being disposed for ex-ample at different angles and accordingly reacting to different central wavelengths .
It is clear to the expert that the detector system can be realized in many different ways. Fig. 15 shows, as an easy-to-service alternative, an arrangement using optical fibers. The basis of the optical arrangement is again Fig. 13. In detector system 133, reflected light beam 132 initially passes through a color filter 161 to check the central wavelength. In following lambda/4 plate 162 the circular polarization is converted into a linear one. An input coupling optical system 153 couples light beam 132 into a waveguide system 154, known beam separators separate the beam into equivalent partial bundles. At the end of each partial bundle there is a polarizer-detector pair 155/156 and 157/158 for the two different polar-izing directions.
~ 2032~87 If the light has the corr~ct wavelength and polarization one of the two detectors 156/15~S receives (in the case of lossfree optics) 5(1,'o of the input intensity. the second receives no light. In the case of a forged ele-ment reflecting unpolarized light. each of the detectors receives 50% of the input intensity. In this wav one can distingl]ish forgery from the original .
Claims (36)
1. A data carrier, in particular a paper of value, document, identity card or the like, having an optically variable security element containing a liquid crystal material, characterized in that the material is a liquid crystal polymer which is present in an oriented form and at room temper-ature as a solid.
2. The data carrier of claim 1, characterized in that the material is a crosslinkable liquid crystal-silicone polymer.
3. The data carrier of claim 1, characterized in that the material is an organopolysiloxane or an organooxysilane or a compound with an orga-nopolysiloxane or an organooxysilane.
4. The data carrier of claim 1, characterized in that the liquid crystal polymer is present as a layer or a film in the security element or in the data carrier.
5. The data carrier of claim 4, characterized in that the carrier films (20) coated with liquid crystal polymer are joined together in pairs with a laminating agent (22) so as to give rise to a symmetrical layer structure (13c. 13d).
6. The data carrier of claim 4, characterized in that at least one surface of the security element is printed with transparent absorbent and/or reflective inks (34, 40) or one layer of the security element is dyed with such inks.
7. The data carrier of claim 6, characterized in that the security ele-ment is applied in a printed and/or inscribed area (60) of the data car-rier.
8. The data carrier of claim 7, characterized in that a normally invis-ible coding (72) is applied to the data carrier in the area of the security element.
9. The data carrier of claim 8, characterized in that the liquid crystal polymer is processed as a film (127).
10. The data carrier of claim 9, characterized in that the film (127) is integrated as a security element into the structure of a multilayer data carrier (120).
11. The data carrier of claim 10, characterized in that the film is the cover film (122, 123) of the data carrier.
12. An optically variable security element for equipping data carriers with liquid crystal material, characterized in that the security element is designed as a multilayer transfer element with at least one layer (56) of liquid crystal polymers.
13. The security element of claim 12, characterized in that layers or surfaces of the transfer element are printed or dyed with transparent absorbent and/or reflective dyes.
14. The security element of claim 12, characterized in that the contour (61) of the transfer element has a predetermined shape in the form of a logo, seal, coat of arms, alphanumeric characters, guilloche pattern or the like.
15. A semifinished product for producing the security element of claim 12, characterized in that a layer (21) or a film (21) made of a liquid crystal polymer is applied to a carrier film (20).
16. The semifinished product for producing a security element of claim 15, characterized in that two coated carrier films (20) are joined together with a laminating agent (22) so as to give rise to a symmetrical layer structure.
17. The semifinished product of claim 15, characterized in that a layer or surface of the semifinished product is printed and/or dyed with dyes.
18. The semifinished product of claim 15, characterized in that it comprises at least a carrier band and a separation layer, a layer with liquid crystal polymer.
19. A method for producing the data carrier according to any one of claims 1 to 18, characterized by following steps:
- applying the liquid crystal material while still liquid to a carrier surface, - orienting the liquid crystal material by the mechanical action of shearing forces, - hardening the oriented material to a solid, - introducing or applying the solid liquid crystal material into or onto the layer structure of the data carrier.
- applying the liquid crystal material while still liquid to a carrier surface, - orienting the liquid crystal material by the mechanical action of shearing forces, - hardening the oriented material to a solid, - introducing or applying the solid liquid crystal material into or onto the layer structure of the data carrier.
20. The method of claim 19, characterized in that the carrier surface is a separate carrier film.
21. The method of claim 19, characterized in that the orientation is performed by doctoring on the liquid crystal material.
22. The method of claim 19, characterized in that the carrier surface is a printing roller onto which the liquid crystal material is directly doctored or rolled and from which the liquid crystal material is transferred to a surface of the data carrier by a printing process.
23. The method of claim 19, characterized in that the hardening is performed by a predefined energy input.
24. The method of claim 23, characterized in that the energy input is provided by irradiation with UV or IR light.
25. The method of claim 23, characterized in that the energy input is provided by the action of an electron beam.
26. The method of claim 19, characterized in that the liquid crystal material forms a self-supporting film on the carrier surface and is detached after hardening.
27. A method for producing the data carrier according to any one of claims 1 to 18, characterized in that the liquid crystal material is disposed in an oriented and hardened form on a carrier film and is transferred from this carrier film to the data carrier or a layer of the data carrier by the transfer method.
28. The method according to any one of claims 19 to 26, characterized in that the hardening of the liquid crystal material is not performed over the entire surface but in the form of patterns, characters or the like, and the unhardened areas are removed after the hardening step.
29. The use of a liquid crystal polymer for protecting and/or identifying the authenticity of data carriers such as papers of value, identify cards or the like.
30. A method for automatically testing the data carrier of claim 1, characterized in that the security element is illuminated by a light source from at least one predetermined angle, and the polarization properties and/or the spectral properties of the reflected light are tested by suitable detector assemblies.
31. The method of claim 30, characterized in that the properties of the reflected light are tested at several lighting and/or viewing angles.
32. An assembly for carrying out the method of claim 30 or 31, characterized by - a light source (129) for illuminating the security element (130) from at least one predetermined angle, - one or more color filters (141, 161) for testing the spectral properties of the reflected light, - a polarization-optical component (152, 162), - a beam splitter (143) for splitting the reflected light into partial beams of different polarization, and - polarizing optical components (148, 149, 155, 157) and detectors (146, 147, 156, 158) for measuring the intensity of the partial beams.
33. The arrangement of claim 32, characterized in that the reflected beam (132) is coupled into a fiber-optical system (154) with an optical system (153), whereby the beam splitter and polarizing components (155, 157) are integrated into the system.
34. The data carrier according to any one of claims 1 to 7, characterized in that the liquid crystal polymer is processed as a film (127).
35. The security element of claim 13, characterized in that the contour (61) of the transfer element has a predetermined shape in the form of a logo, seal, coat of arms, alphanumeric characters, guilloche pattern or the like.
36. The method of claim 27, characterized in that the hardening of the liguid crystal material is not performed over the entire surface but in the form of patterns, characters or the like, and the unhardened areas are removed after the hardening step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3942663A DE3942663A1 (en) | 1989-12-22 | 1989-12-22 | DATA CARRIER WITH A LIQUID CRYSTAL SECURITY ELEMENT |
| DEP3942663.7 | 1989-12-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2032587A1 CA2032587A1 (en) | 1991-06-23 |
| CA2032587C true CA2032587C (en) | 1996-07-09 |
Family
ID=6396250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002032587A Expired - Fee Related CA2032587C (en) | 1989-12-22 | 1990-12-18 | Data carrier having a liquid crystal security element |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0435029B2 (en) |
| JP (1) | JP3244278B2 (en) |
| AT (1) | ATE126135T1 (en) |
| CA (1) | CA2032587C (en) |
| DE (2) | DE3942663A1 (en) |
| ES (1) | ES2075871T5 (en) |
Cited By (2)
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|---|---|---|---|---|
| US7488002B2 (en) | 1998-07-02 | 2009-02-10 | Securency Pty Limited | Security and/or value document |
| WO2017137719A1 (en) * | 2016-02-11 | 2017-08-17 | De La Rue International Limited | Improvements in secuirty devices |
Families Citing this family (104)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| GB0615921D0 (en) | 2006-08-10 | 2006-09-20 | Rue De Int Ltd | Photonic crystal security device |
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| GB2442711B (en) | 2006-10-10 | 2011-04-13 | Rue De Int Ltd | Improvements in security devices |
| JP4959304B2 (en) | 2006-11-22 | 2012-06-20 | 日本発條株式会社 | Identification medium, identification method, and identification apparatus |
| DE102007022437A1 (en) * | 2007-05-10 | 2008-11-13 | Leonhard Kurz Gmbh & Co. Kg | Process for producing a crosslinked liquid-crystal layer and device for carrying out the process |
| DE102007023560B4 (en) | 2007-05-21 | 2009-02-05 | Ovd Kinegram Ag | Multi-layer body |
| DE102007034716A1 (en) | 2007-07-23 | 2009-01-29 | Giesecke & Devrient Gmbh | security element |
| GB0720550D0 (en) | 2007-10-19 | 2007-11-28 | Rue De Int Ltd | Photonic crystal security device multiple optical effects |
| GB2457911B (en) | 2008-02-27 | 2010-05-12 | Rue De Int Ltd | Improved method for producing an optically varible security device |
| DE102008026216B4 (en) | 2008-05-30 | 2010-07-29 | Polyic Gmbh & Co. Kg | Electronic switch |
| FR2933428B1 (en) * | 2008-07-03 | 2010-08-27 | Arjowiggins Licensing Sas | SECURITY ELEMENT WITH VARIABLE OPTICAL EFFECT AND SHEET OR SECURITY DOCUMENT OR ARTICLE COMPRISING SAME |
| DE102008061608A1 (en) | 2008-12-11 | 2010-06-17 | Giesecke & Devrient Gmbh | security element |
| DE102009016533A1 (en) * | 2009-04-06 | 2010-10-07 | Giesecke & Devrient Gmbh | Piezochrome safety element based on liquid crystal |
| GB0906366D0 (en) | 2009-04-14 | 2009-05-20 | Rue De Int Ltd | Security device |
| GB2474903B (en) | 2009-10-30 | 2012-02-01 | Rue De Int Ltd | Improvements in security devices |
| GB2476228B (en) | 2009-11-19 | 2012-02-01 | Rue De Int Ltd | Improvements in security devices |
| DE102012003601A1 (en) | 2012-02-21 | 2013-08-22 | Giesecke & Devrient Gmbh | Printing process with Passer between print and watermark |
| CN102759441A (en) * | 2012-07-20 | 2012-10-31 | 西北工业大学 | Multiband polarization imaging anti-counterfeiting element identification system |
| IN2014MU03621A (en) | 2013-11-18 | 2015-10-09 | Jds Uniphase Corp | |
| DE102015004072A1 (en) | 2015-03-30 | 2016-10-06 | Giesecke & Devrient Gmbh | Multicolored security element with effect colors |
| WO2020217254A1 (en) * | 2019-04-20 | 2020-10-29 | Shilpan Patel | Robust colour shift security film with wide spectrum complex spectral values and security thread made therefrom |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU488652B2 (en) * | 1973-09-26 | 1976-04-01 | Commonwealth Scientific And Industrial Research Organisation | Improvements in or relating to security tokens |
| GB2109304B (en) * | 1981-01-08 | 1984-05-10 | Lucy Ann Boutaleb | Identification of articles |
| DE3110048A1 (en) * | 1981-03-16 | 1982-09-30 | Consortium für elektrochemische Industrie GmbH, 8000 München | "COMPOSITIONS CONTAINING LIQUID CRYSTALLINE PHASES BASED ON CYCLIC ORGANOPOLYSILOXANS, THEIR PRODUCTION AND THEIR USE" |
| DE3119459A1 (en) * | 1981-05-15 | 1982-12-09 | Consortium für elektrochemische Industrie GmbH, 8000 München | LIQUID-CRYSTALLINE PROPERTIES WITH CROSS-LINKED ORGANOPOLYSILOXANES |
| CH653161A5 (en) * | 1981-10-27 | 1985-12-13 | Landis & Gyr Ag | DOCUMENT WITH A SECURITY CHARACTERISTIC AND METHOD FOR CHECKING THE DOCUMENT FOR AUTHENTICITY. |
| JPS5988780A (en) * | 1982-11-08 | 1984-05-22 | アメリカン・バンク・ノ−ト・カムパニ− | Making of optical refraction recording body and optical refraction pattern |
| DE3331515A1 (en) * | 1983-09-01 | 1985-03-21 | Merck Patent Gmbh, 6100 Darmstadt | TRIALKANOYLOXYSILANES |
-
1989
- 1989-12-22 DE DE3942663A patent/DE3942663A1/en not_active Withdrawn
-
1990
- 1990-12-05 ES ES90123341T patent/ES2075871T5/en not_active Expired - Lifetime
- 1990-12-05 DE DE59009504T patent/DE59009504D1/en not_active Expired - Lifetime
- 1990-12-05 AT AT90123341T patent/ATE126135T1/en not_active IP Right Cessation
- 1990-12-05 EP EP90123341A patent/EP0435029B2/en not_active Expired - Lifetime
- 1990-12-18 CA CA002032587A patent/CA2032587C/en not_active Expired - Fee Related
- 1990-12-21 JP JP40517890A patent/JP3244278B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7488002B2 (en) | 1998-07-02 | 2009-02-10 | Securency Pty Limited | Security and/or value document |
| WO2017137719A1 (en) * | 2016-02-11 | 2017-08-17 | De La Rue International Limited | Improvements in secuirty devices |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0435029A3 (en) | 1991-09-18 |
| EP0435029B1 (en) | 1995-08-09 |
| EP0435029B2 (en) | 2003-01-02 |
| CA2032587A1 (en) | 1991-06-23 |
| ATE126135T1 (en) | 1995-08-15 |
| ES2075871T3 (en) | 1995-10-16 |
| JP3244278B2 (en) | 2002-01-07 |
| JPH04144796A (en) | 1992-05-19 |
| DE59009504D1 (en) | 1995-09-14 |
| DE3942663A1 (en) | 1991-06-27 |
| EP0435029A2 (en) | 1991-07-03 |
| ES2075871T5 (en) | 2003-07-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |