Abstract
A method for producing a security document, with a thermographic substrate wherein the thermographic substrate is caused to undergo a color change depending on temperature effect in at least one first region A film element is arranged in such a way that the film element is arranged between the at least one first region of the thermographic substrate and a thermal print head. At least one first item of information is introduced by means of the thermal print head by activation of the color change in the at least one first region of the thermographic substrate, wherein the thermal print head, during the introduction of the at least one first item of information is in contact with the film element in such a way that the temperature effect causing the activation of the color change is transferred from the thermal print head through the film element to the at least one first region of the thermographic substrate.
Claims
1. A method for producing a security document, with a thermographic substrate, the method comprising: (a) providing the thermographic substrate, the thermographic substrate having a thermosensitive layer comprising color-producing substances which, under the effect of warmth, react chemically, such that the thermographic substrate is caused to undergo a color change depending on temperature effect in at least one first region; (b) arranging a film element in such a way that the film element is arranged between the at least one first region of the thermographic substrate and a thermal print head, the film element having a transfer ply comprising one or more first layers; and (c) introducing at least one first item of information by means of the thermal print head by: i) warming the thermographic substrate to chemically react the color-producing substances of the thermosensitive layer in the at least one first region of the thermographic substrate, and ii) applying the transfer ply of the film element in the at least one first region of the thermographic substrate, wherein the thermal print head, during the introduction of the at least one first item of information while applying the transfer ply of the film element in the at least one first region of the thermographic substrate, is in contact with the film element, in such a way that the temperature effect causing the activation of the color change is transferred from the thermal print head through the film element to the at least one first region of the thermographic substrate.
2. The method according to claim 1, wherein, in step c), by color change of the thermographic substrate in the at least one first region, a first color is produced and the one or more first layers of the film element which are applied to the security document, in the at least one first region in step c), are formed colored in a second color at least in regions, wherein the first color and the second color are different colors, of the RGB color space.
3. The method according to claim 1, wherein the film element arranged in step b) has one or more dyes and/or one or more adhesives, and in step c) the one or more dyes and/or the one or more adhesives are melted on during application.
4. The method according to claim 1, wherein the film element arranged in step b) has a replication varnish layer, a detachment layer and a transparent protective varnish layer, and wherein a relief structure is molded into the replication varnish layer at least in areas, and wherein the detachment layer is arranged between the replication varnish layer and the transparent protective layer, and wherein the replication varnish layer is facing the thermal print head, and wherein, in step c), the transparent protective varnish layer is applied to the security document, by means of the thermal print head in such a way that a relief structure that is inverted with respect to the relief structure of the replication varnish layer is molded into the transparent protective varnish layer.
5. The method according to claim 1, wherein, in at least one second region, the temperature effect causing the activation of the color change is selected such that, in the at least one second region, the at least one first item of information is not introduced into the thermographic substrate and the one or more first layers of the film element are applied to the security document, for the representation of at least one second item of information by means of the thermal print head.
6. The method according to claim 5, wherein the at least one first region and the at least one second region lie in the maximum recording range of the thermal print head, wherein the maximum recording range corresponds to the maximum area of the thermal print head, with which the thermal print head is in contact with the film element during the introduction of the first item of information in step c).
7. The method according to claim 1, wherein the thermographic substrate provided in step a) is caused to undergo at least two color changes depending on the temperature effect in at least two first regions, wherein the at least two color changes are caused when at least two different temperature limits are exceeded.
8. The method according to claim 1, wherein the thermographic substrate provided in step a), at least in regions, has one or more second layers that are transparent at least in regions, wherein the one or more second layers are arranged between the film element and the thermographic substrate, when observed perpendicular to the plane spanned by the upper side of the thermographic substrate, and wherein, in step c), the temperature effect causing the activation of the color change is transferred through the one or more second layers to the at least one first region of the thermographic substrate.
9. The method according to claim 1, wherein, in step c), the temperature effect is more than 50 C.
10. The method according to claim 1, wherein, in step c), the thermal print head, at least in regions, has a temperature of more than 70 C.
11. The method according to claim 1, wherein the method is carried out by means of a thermal transfer printer.
12. The method according to claim 1, further comprising applying at least one sealing layer to the security document.
13. The method according to claim 12, wherein, the at least one sealing layer is applied by means of cold lamination.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Embodiment examples of the invention are explained below by way of example with the aid of the accompanying figures which are not drawn to scale.
(2) FIG. 1a schematically shows a method step for producing a document
(3) FIG. 1b and FIG. 1c show schematic top views and sectional representations of design variants of a document
(4) FIG. 2a schematically shows a method step for producing a document
(5) FIG. 2b shows a schematic sectional representation and top view of a document
(6) FIG. 3a schematically shows a method step for producing a document
(7) FIG. 3b and FIG. 3c show schematic top views and sectional representations of design variants of a document
(8) FIG. 4 to FIG. 6 schematically show method steps for producing a document
(9) FIG. 7a and FIG. 7b show schematic sectional representations of design variants of a thermographic substrate
(10) FIG. 8a to FIG. 8p show schematic sectional representations of design variants of a film element
(11) FIG. 9 to FIG. 12 show schematic top views and sectional representations of design variants of a document
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(12) FIG. 1a shows a method step for producing a document 1. For this purpose, as shown in FIG. 1a, a document 1 is provided with a thermographic substrate 2, which can be locally caused to undergo a color change 15 depending on temperature effect. Furthermore, a film element 5 is arranged between a thermal print head 6 which produces the temperature effect, and the thermographic substrate 2. It is possible that the film element 5 comprises one or more layers. The thermal print head 6 has a plurality of heating elements not shown in more detail.
(13) The upper side of the thermographic substrate 2 spans a plane which, as shown in FIG. 1b, is parallel to a plane spanned by the x-coordinate axis 25 and the y-coordinate axis 26. As shown in FIG. 1a, the z-coordinate axis 27 is perpendicular to this plane and thus perpendicular to the plane spanned by the upper side of the thermographic substrate 2.
(14) The thermographic substrate 2 comprises a thermosensitive layer 31 and a base layer 30. In FIG. 1a, the thermosensitive layer 31 and the base layer 30 are two layers separated from each other. Furthermore, it is also possible that a thermosensitive coating applied to the base layer 30 extends into the volume of the base layer 30, at least in regions.
(15) The base layer 30 is preferably a paper layer, in particular with a layer thickness between 35 m and 400 m. The layer thickness of the base layer 30 in FIG. 1a is 125 m. The base layer further preferably has a weight per unit area of 35 g/m.sup.2 to 400 g/m.sup.2, oven-dry. Furthermore, it is also possible that the base layer 30 consists of one or more paper and/or plastic layers and in particular of a succession of paper and plastic layers.
(16) The thermosensitive layer 31 preferably comprises color-producing substances which, under the effect of warmth, react chemically and activate the color change 15. The thermosensitive layer 31 preferably has pigments, binders, colorformers, developers and auxiliary materials. Leuco dyes which appear colorless in crystalline form or in a pH-neutral environment are preferably used as colorformers. In a melt with an acid environment, the leuco dyes appear colored because of the opened lactone ring. For example, such leuco dyes can be immobilized in a matrix with an acid. Heating the matrix above the melting point results in a chemical reaction, such that the leuco dyes now appear colored due to absorption of light from the visible wavelength range. Phenols such as Bisphenol A (BPA) or Bisphenol S (BPS) can be used as developers for example. Further examples of colorformers are triarylmethane-based dyes, diphenylmethane-based dyes, spiro-based dyes and fluorane-based dyes. Furthermore, the developers can be selected from organic or inorganic development materials. Examples of inorganic development materials are activated clay, attapulgite, colloidal silica, aluminum silicate and the like. Examples of organic development materials are phenolic compounds, salts of phenolic compounds or aromatic carboxylic acids and the like with polyvalent metals such as e.g. zinc, magnesium, aluminum, calcium, titanium, manganese, tin, nickel and the like and/or pyridine complexes of zinc thiocyanates.
(17) After drying, the thermosensitive layer 31 preferably has an application weight of from 1 g/m.sup.2 to 10 g/m.sup.2, oven-dry, preferably 2 g/m.sup.2 to 7 g/m.sup.2, oven-dry. As shown in FIG. 1a, under the effect of warmth, the color-producing substances in the thermosensitive layer 31 activate a color change 15 from colorless to black in the region 10a. Furthermore, it is also possible that a color change between two different colors is activated, for example from yellow to violet. Thus, in addition to the color change 15 from colorless to black, shown in FIG. 1a, a color change from colorless to colored, a color change between two different colors or a change in contrast, for example from dark green to light green is possible.
(18) To activate the color change 15 in the region 10a, as shown in FIG. 1a, the thermal print head 6 is in contact with the film element 5, in such a way that the temperature effect causing the activation of the color change 15 is transferred from the thermal print head 6 through the film element 5 to the region 10a of the thermographic substrate. The thermal energy generated by the thermal print head 6 is transmitted through the film element 5, so that the thermosensitive layer 31 is activated in the region 10a and prompted to undergo the color change 15. The color change 15 activated in the region 10a represents an item of information. Furthermore, it is possible that several regions in which a color change has been activated, represent an item of information. As shown in FIG. 1a, the thermographic substrate 2 is moved along a feed direction 28 in the direction of the x axis in such a way that regions in which a color change 15 has been activated, represent the item of information 20a. Furthermore, it is also possible that the thermal print head 6 is moved with respect to the thermographic substrate 2 to introduce the item of information 20a into the thermographic substrate 2. In the case shown, the thermal print head 6 would be moved with respect to the thermographic substrate 2 against the feed direction 28.
(19) The film element 5 is advantageously in contact with the document 1 and/or the thermographic substrate 2 with the side facing away from the thermal print head 6 in such a way that the temperature effect causing the activation of the color change 15 is transferred from the thermal print head 6 through the film element 5 to the region 10a of the thermographic substrate 2.
(20) The thermal print head 6 preferably has a field with a plurality of heating elements such as for example heating resistors. The resolution of the item of information introduced by means of the thermal print head is advantageously more than 150 dpi, preferably more than 300 dpi, further preferably more than 600 dpi. The maximum width of the thermal print head 6, with which the thermal print head is in contact with the film element 5 during the introduction of the item of information is preferably at least 5 mm, preferably at least 10 mm, further preferably at least 50 mm, still further preferably at least 100 mm.
(21) In FIG. 1a, during the activation of the color change 15, the thermal print head 6 has a temperature between 70 C. and 220 C. and the temperature effect indicated hereby in the region 10a of the thermographic substrate 2 is between 50 C. and 200 C.
(22) Depending on the feed of the thermographic substrate 2 in the direction of the feed direction 28 and/or activation of the heating elements of the thermal print head 6, it is possible to vary the color change 15 in size and shape. Thus, for example, the region 10v has a greater extent than the region 10a in the direction of the x-axis.
(23) FIG. 1b and FIG. 1c show schematic top views and sectional representations of design variants of a document 1.
(24) Thus, FIG. 1b shows a document 1 with a thermographic substrate 2, wherein the document 1 has the item of information 20b in the region 10b, the item of information 20c in the region 10c and the item of information 20d in the region 10d. The items of information 20b, 20c and 20d are each introduced into the thermographic substrate 2 via the color changes 15. The color changes 15 representing the items of information 20b, 20c and 20d are formed patterned as shown in FIG. 1b. A pattern can, for example, be a graphically formed outline, a figural representation, an image, a motif, a symbol, a logo, a portrait, an alphanumeric character, a text and the like. Thus, a barcode is produced as item of information 20b by the color changes 15 activated in the thermographic substrate 2 in the region 10b. Furthermore, the color change 15 in the region 10c represents a cross as item of information 20c and the color changes 15 in the region 10d are formed in the shape of alphanumeric characters as text information.
(25) FIG. 1c shows a document 1 with a thermographic substrate 2, wherein the document 1 has the item of information 20e in the region 10e, the item of information 20f in the region 10f and items of information in the form of alphanumeric characters in the regions 10g and 10h. Thus, a star is produced as item of information 20e by the color change 15 activated in the thermographic substrate 2 in the region 10e. Furthermore, the color changes 15 in the region 10f are formed in such a way that they represent a barcode as item of information 20f.
(26) FIG. 2a schematically shows a method step for producing a document 1 with a thermographic substrate 2. The method step shown in FIG. 2a corresponds to the method step shown in FIG. 1a with the difference that the film element 5 arranged between the thermal print head 6 which produces the temperature effect, and the thermographic substrate 2, comprises one or more first layers and one carrier layer 41, wherein the one or more first layers are transferred as transfer ply 40 in regions from the carrier layer 41 onto the document 1 by means of the thermal print head 6. The transfer ply 40 is thus formed by the one or more first layers of the film element.
(27) The carrier layer 41 is preferably a layer made of plastic, for example of polyester with a layer thickness between 6 m and 125 m. The carrier layer 41 shown in FIG. 2a is made of polyethylene terephthalate (=PET) with a layer thickness of 4.5 m. Between the carrier layer 41 and the transfer ply 40, a detachment layer is advantageously applied, which is preferably formed as a wax layer or alternatively from a strongly filming acrylate, which facilitates the detachment of the transfer ply 40 from the carrier layer 41.
(28) As shown in FIG. 2a, during the introduction of the color change 15 in the region 10i, the transfer ply 40 of the film element 5 is applied to the document 1 in the region 10i. Thus, in the region 10i, on the one hand the color change 15 is caused by transferring the temperature effect from the thermal print head 6 through the film element 5 to the region 10i of the thermographic substrate 2, and on the other hand, the transfer ply 40 of the film element 5 is applied to the document 1 in the region 10i. The transfer ply 40 which is applied to the document 1 with the thermographic substrate 1, is thus arranged accurately fitting, i.e. precisely positioned relative to the color change 15 in the region 10i. As shown in FIG. 2a, thus in all regions in which a color change 15 is caused, the transfer ply 40 is also applied to the document 1. The transfer ply 40a applied to the document 1 is correspondingly removed from the film element 5, with the result that the transfer ply 40e is removed from the film element 5 in regions.
(29) In FIG. 2a, during the activation of the color change 15 in the region 10i and the application of the first layers in the region 10i, the thermal print head 6 has a temperature between 70 C. and 220 C. The temperature effect induced by the thermal print head 6 in the region 10i of the thermographic substrate 2 is between 50 C. and 200 C.
(30) FIG. 2b shows a schematic sectional representation and top view of a document 1. FIG. 2b thus shows a document 1 with a thermographic substrate 2, wherein the document 1 has an item of information in each of the regions 10j, 10k and 10l. Furthermore, a color change 15 is activated in the regions 10j, 10k and 10l in the thermographic substrate 2, to represent the item of information. Furthermore, the transfer ply 40a is applied to the document 1 accurately fitting the color changes 15 in the regions 10j, 10k and 10l. The transfer ply 40a in the regions 10j, 10k and 10l is formed transparent. Furthermore, it is possible that the transfer ply 40a in the regions 10j, 10k and 10k is formed opaque, translucent or semi-transparent. Thus, for example, the transfer ply 40a can be formed opaque and red in color in the region 10k.
(31) FIG. 3a schematically shows a method step for producing a document 1 with a thermographic substrate 2. The method step shown in FIG. 2a corresponds to the method step shown in FIG. 2a, with the difference that in the region 11a, the temperature effect causing the activation of the color change 15 has been selected such that the color change 15 is not activated in the region 11a and the transfer ply 40 of the film element 5 is applied to the document 1 to represent an item of information 21a by means of the thermal print head 6. As shown in FIG. 3a, the regions in which both the color change in the thermographic substrate 2 is activated and the transfer ply 40a is applied to the document 1 form an item of information 20a. Furthermore, the regions in which only the transfer ply 40a is applied to the document 1 form an item of information 21a. Thus, for example, items of information, such as the item of information 21a, which have a lesser relevance can be applied solely means of the transfer ply 40a, and items of information, such as the item of information 20a, which have a high relevance, for example an expiry date, can both be applied by means of the transfer ply 40 and introduced by the color change 15 in the thermographic substrate 2.
(32) The temperature effect which is required for activation of the color change 15 in the thermographic substrate 2, is preferably higher than the temperature effect which is required for application of the transfer ply 40a to the document 1. The energy of the temperature effect for application of the transfer ply 40a to the document 1 is advantageously less than 82.5%, preferably less than 80%, of the energy of the temperature effect which is required for activation of the color change 15 in the thermographic substrate 2. Because of this lower energy requirement of the temperature effect for application of the transfer ply 40a to the document 1, it is thus possible, for example in the region 11a to apply solely the transfer ply 40a to the document 1, but not to activate the color change 15 in the thermographic substrate. In FIG. 3a, during the activation of the color change 15 in the region 10i and the application of the transfer ply in the region 10i, the thermal print head 6 has a temperature between 70 C. and 220 C., while, during the application of the transfer ply 40a in the region 11a, the thermal print head 6 has had a temperature between 57.75 C. and 181.5 C. FIG. 3b and FIG. 3c show schematic top views and sectional representations of design variants of a document 1.
(33) FIG. 3b shows thus shows a document 1 with a thermographic substrate 2, wherein the document 1 has an item of information in each of the regions 10m, 10n and 11b. Furthermore, a color change 15 is activated in the regions 10m and 10n in the thermographic substrate 2 to represent the item of information. Furthermore, the transfer ply 40a is applied to the document 1 accurately fitting the color changes 15 in the regions 10m and 10n. Solely the transfer ply 40a is applied to the document 1 in the region 11b. The transfer ply 40a is formed transparent in the region 10m. In the regions 10n and 11b, the transfer ply 40a is formed colored in different colors, for example of the Pantone color system (Pantone Matching SystemPMS).
(34) FIG. 3c shows a document 1 with a thermographic substrate 2, wherein the document 1 has an item of information in each of the regions 10o, 10p and 11c. Furthermore, a color change 15 is activated in the regions 10o and 10p in the thermographic substrate 2 to represent the item of information. Furthermore, the transfer ply 40a is applied to the document 1 accurately fitting the color changes 15 in the regions 10o and 10p. Solely the transfer ply 40a is applied to the document 1 in the region 11c. The transfer ply 40a is formed transparent in the region 10o. In the regions 10p and 11c, the transfer ply 40a is formed colored in different colors, for example in red and green of the RGB color space.
(35) FIG. 4 schematically shows method steps for producing a document 1. The method step shown in FIG. 4 corresponds to the method step shown in FIG. 3a, with the difference that the region 10r and the region 11r are situated in the maximum recording range 12 of the thermal print head 6. The maximum recording range 12 of the thermal print head 6 corresponds to the maximum area of the thermal print head 6, with which the thermal print head 6 is in contact with the film element 5 during the activation of the color change 15.
(36) The thermal print head 6 in FIG. 4 here has the heating elements 6h. The heating elements 6h of the thermal print head 6 touch the film element 5 in the recording range 12. Furthermore, the heating elements 6h of the thermal print head 6 are in contact with the film element 5, in such a way that the film element 5 also touches the document 1 over an area which corresponds to the recording range 12. The heating elements 6h of the thermal print head generate a temperature effect in the region 10r, such that, in the region 10r, both the color change 15 is activated in the thermographic substrate 2, and the transfer ply 40a is applied to the document 1. In the region 11r, the heating elements 6h of the thermal print head generate a temperature effect such that, in the region 11r, solely the transfer ply 40a is applied to the document 1. As already explained, the required effect of warmth or activation of the color change 15 in the thermographic substrate 2 is preferably higher than the effect of heat for application of the transfer ply 40a to the document 1, with the result that it is hereby made possible solely to apply the transfer ply 40a to the document 1 in the region 11r, wherein the heating elements 6h of the thermal print head in the region 11r have a lower temperature than the heating elements in the region 10r. The heating elements 6h in the region 10r can thus, for example, have a temperature of 100 C. and the heating elements 6h in the region 11r have a temperature of 80 C.
(37) FIG. 5 shows a method step for producing a document 1. The method step shown in FIG. 5 corresponds to the method step shown in FIG. 1a, with the difference that the thermographic substrate 2 has second layers 60, wherein the second layers 60 are arranged between the film element 5 and the thermographic substrate 2. The second layers 60 are preferably formed transparent at least in regions, with the result that the color change 15 in the thermographic substrate 2 activated in the region 10a is recognizable through the second layers 60 that are transparent in regions. In FIG. 5, the temperature effect causing the activation of the color change 15 is transferred both through the second layers 60 and through the film element 5 to the region 10a of the thermographic substrate 2.
(38) FIG. 6 shows a method step for producing a document 1. The method step shown in FIG. 6 corresponds to the method step shown in FIG. 3a, with the difference that the thermographic substrate 2 has one or more second layers 60, wherein the second layers 60 are arranged between the film element 5 and the thermographic substrate 2. As already explained, the temperature effect causing the activation of the color change 15 is transferred both through the second layers 60 and through the film element 5 to the region 10a of the thermographic substrate 2.
(39) Design variants of the thermographic substrate 2 of FIG. 7a and FIG. 7b are explained below.
(40) Thus FIG. 7a shows a thermographic substrate 2 which comprises a base layer 30, a thermosensitive layer 31, a protective layer 32, an intermediate layer 33 and a layer 34. With respect to the layers 30 and 31, reference is made here to the above statements.
(41) The protective layer 32, also referred to as a coating, is preferably a polymer layer, in particular a polymer coating. Typical polymers here are PVA (polyvinyl alcohol), also modified PVA as well as copolymers with acrylic acids (acrylates) which result with cross-linking temperatures of approximately less than 70 C. (the cross-linking temperature must be below the reaction temperature of the thermally sensitive layer). Typical grammages lie between 1 g/m.sup.2 and 5 g/m.sup.2 oven-dry. The thickness of the protective layer 32 is usually between 1 m, and 3 m. (The thicker the layer, the better the protection, but the thermosensitive layer 31 becomes all the more insulated and thus the dynamic sensitivity becomes all the more impaired.) Pigments, for example PCC, and pyrogenic silicic acid, can also be added to the composition for the protective layer 32. The more pigments are contained, the better the printability of the thermographic substrate 2, for example by means of inkjet or offset printing, but the less good the impermeability and thus the protective function of the coating. In addition, part of the protective layer 32 has lubricants added, which are melted on during the thermal printing, make possible sliding of the thermal print head 6 and thus reduce abrasion. These are usually stearates (for example zinc or calcium soaps). As these substances have oily contents, the printability for example by means of inkjet or offset printing of the protective layer 32 diminishes in the case of higher contents. The protective layer 32 protects the thermographic substrate 2 for example vis--vis mechanical stress, chemical influences (for example against plasticizers), environmental influences, such as air humidity, or vis--vis printing optionally applied to the thermographic substrate 2. Furthermore, it is possible that the protective layer 32 is applied both to the upper side of the thermographic substrate 2 and to the lower side of the thermographic substrate 2.
(42) The intermediate layer 33 is preferably a paper layer, in particular a paper coating which consists mainly of mineral pigments (for example calcium carbonate, kaolin) and/or hollow sphere pigments and polymer binders. The layer thickness is between 2 m and 12 m, the grammage between 3 g/m.sup.2 and 15 g/m.sup.2 oven-dry. The intermediate layer 33 makes possible an even and smooth surface, to which the thermosensitive layer 31 is applied. A high resolution and a high image quality are hereby made possible. Furthermore, a heat input into the base layer 30 is prevented and thus the sensitivity properties of the thermosensitive layer 31 are improved.
(43) The protective layer 32 and/or the intermediate layer 33 can also be arranged on both sides of the base layer 30 in order to confer a good flatness on the thermographic substrate 2, but also to improve the impermeability (for example against starch solution) or the printability (pigment coating). The flatness is partially optimized merely with a rehumidifying system, i.e. water.
(44) The layer 34 is preferably a printed color layer 34 with a layer thickness between 0.8 m and 10 m. Furthermore, it is possible that the layer 34 is a layer which has pigments which, in the case of irradiation with electromagnetic radiation, preferably in the case of irradiation with UV and/or IR light, emit light from the range of the wavelength range visible to the human eye, in particular in the wavelength range from 380 nm to 780 nm. It is possible that the layer 34 is applied in regions. Furthermore, it is possible that the regions in which the layer 34 is applied in regions, are formed patterned, for example in the form of a logo or alphanumeric character. Furthermore, a pattern can, for example, be a graphically formed outline, a figural representation, an image, a motif, a symbol, a portrait, a text and the like.
(45) FIG. 7b shows a thermographic substrate 2, which has second layers 60 in the region 14. With respect to the design of the layers 30, 31, 32 and 33, reference is made here to the above statements. The second layers 60 are preferably formed transparent at least in regions. Furthermore, it is also possible that the second layers 60 are stained at least in regions. It is thus also possible that the second layers 60 are formed opaque at least in regions.
(46) The second layers 60 comprise a protective varnish layer 60a, a replication varnish layer 60b, a reflective layer 60c and a bonding layer 60d. The layers 60b and 60c here form a decorative layer 61. The protective varnish layer 60a is preferably formed transparent. It is also possible that the protective varnish layer 60a is stained at least in regions. The protective varnish layer 60a preferably has a layer thickness of 1 m. The protective varnish layer 60a is preferably a layer of PMMA, PVC, acrylate and/or carnauba wax.
(47) The replication varnish layer 60b preferably consists of a thermoplastic replication varnish layer with a layer thickness between 1 m and 5 m. In the surface of the replication layer 60b oriented to the reflective layer 60c, a relief structure is molded at least in regions by means of a corresponding replication tool using heat and pressure, with the use of a thermoplastic replication layer. Furthermore, it is also possible that the replication varnish layer 60b is formed by a UV-crosslinkable varnish and the relief structure is molded into the replication varnish layer 60b by means of UV replication. The relief structure is molded onto the uncured replication varnish layer 60b by the action of a stamping tool and the replication varnish layer 60b is cured before and/or directly during and/or after the molding by irradiation with UV light.
(48) The relief structures can be the relief structure of a 2D/3D hologram, which is generated holographically and is copied onto a replication master. Furthermore, the relief structures can also be computer-generated holograms and diffractive elements, for example a Kinegram. Such relief structures preferably have a spatial frequency between 100 lines/mm and 5000 lines/mm and optionally have a plurality of different regions which are covered with relief structures which differ in their spatial frequency, their azimuth angle and/or relief form, and thus generate a desired optically variable appearance. Furthermore, the relief structures can also be relief structures which form mat structures, in particular anisotropic mat structures. By anisotropic mat structures is meant here mat structures the scattering characteristics of which are dependent on the observation angle and thus exhibit an optically variable appearance. These mat structures are preferably generated holographically, but can also be formed by a corresponding computer-generated arrangements of diffractive elements.
(49) Furthermore, it is possible that the relief structures form refractive elements, for example lenses, microlens grids or microprisms. Furthermore, it is also possible that the relief structures form a zero-order diffraction structure. These diffraction structures are formed by gratings, in particular regular gratings, for example crossed gratings or linear gratings, in which the spacing of the individual structural elements with respect to each other is smaller than a wavelength A in the visible light range. A striking optically variable security feature is provided by such relief structures, in which a color change is shown to the observer on turning.
(50) The reflective layer 60c is preferably a metal layer and/or an HRI or LRI layer (HRIhigh refraction index, LRIlow refraction index).
(51) It is thus possible that the reflective layer 60c is formed as a metal layer made of chromium, aluminum, gold, copper, silver or an alloy of such metals. The metal layer is preferably vapor-deposited in a vacuum in a layer thickness of from 10 nm to 150 nm.
(52) Furthermore, it is also possible that the reflective layer 60c is formed by a transparent reflective layer, preferably a thin or finely-structured metallic layer or a dielectric HRI or LRI layer. Such a dielectric reflective layer consists, for example, of a vapor-deposited layer made of a metal oxide, metal sulfide, e.g. titanium oxide etc. with a thickness of from 25 nm to 500 nm.
(53) Furthermore, it is possible that the reflective layer 60c is shaped in regions. It is also possible that the reflective layer 60c is formed patterned. A pattern can, for example, be a graphically formed outline, a figural representation, an image, a motif, a symbol, a logo, a portrait, an alphanumeric character, a text and the like. For this purpose, the reflective layer 60c can be structured by means of known processes, in particular removed in regions. For example, this can take place by means of known etching processes and/or washing processes.
(54) In FIG. 7b, the layers 60b and 60c form the decorative layer 61, providing a security feature. It is however also possible that the decorative layer 61 has one or more layers providing the security feature, which contain one or more elements selected from the group: a security print, a UV or IR print, a microprint, a layer containing optically variable pigments, a refractive element, a diffractive element, an anisotropic mat structure, a relief hologram, a volume hologram, a zero-order diffraction structure, a thin film layer element and/or a cross-linked liquid crystal layer generating a color shift effect dependent on the viewing angle.
(55) The bonding layer 60d is preferably a cold adhesive layer, by means of which the second layers 60 are applied to the layer 32. By cold adhesive layer is here meant an adhesive layer with which the adhesive force provided by the adhesive layer is activated between the layers 60c, 32 surrounding the cold adhesive layer solely by pressing the layers 60c and 32 together, i.e. is activated without using heat. Conventional adhesives curing without the effect of pressure and irradiation or adhesives curing under the effect of pressure are used as cold adhesives for example. Furthermore, it is also possible that a UV-curable adhesive layer is used. The curing of the UV-curable adhesive layer preferably takes place with UV radiation of a wavelength between approximately 250 nm and approximately 400 nm. The bonding layer 60d is preferably formed transparent in the wavelength range visible to the human eye, in particular formed transparent and clear. By transparent is meant a transmissivity in the wavelength range visible to the human eye of more than 50%, further preferably more than 80%, further preferably of 90%. By clear is meant a layer in which less than 50%, further preferably less than 80% of the light transmitted through the layer is scattered. The bonding layer 60d preferably has a layer thickness between 1 m and 10 m, preferably between 1 m and 5 m.
(56) Advantageously, the second layers 60 are applied to the thermographic substrate by means of cold-embossing, with the result that undesired color changes in the thermosensitive layer 31 are prevented during application of the second layers 60.
(57) Design variants of a film element 5 or of the first layers of a film element 5 are explained below. FIG. 8a to FIG. 8p thus show sectional representations of design variants of a film element 5. The film elements of FIG. 8b to FIG. 8p here have first layers which can be applied to a document. Thus, the first layers of the film elements 5 are formed as transfer plies 40, wherein the transfer plies 40 are applied to a document by means of a thermal print head. It is thus possible that in particular the film elements of FIG. 8b to FIG. 8p are transfer films, in particular thermal transfer films.
(58) FIG. 8a shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41 and a sliding layer 43. With respect to the carrier layer 41, reference is made here to the above statements. The heat-resistant layer 42 and the sliding layer 43 are layers of polyester resin and polysiloxane. The heat-resistant layer 42 and the sliding layer 43 preferably each have an application weight of 0.25 g/m.sup.2. The film element 5 of FIG. 8a is a film element that has no transfer ply which can be transferred to a document.
(59) FIG. 8b shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44 and an adhesive layer 45. With respect to the layers 41 and 42, reference is made here to the above statements. The transparent protective varnish layer 44 is, for example, a layer of polymethyl methacrylate, PVC, acrylate and/or carnauba wax. The transparent protective varnish layer 44 preferably has an application weight of 0.4 g/m.sup.2. The adhesive layer 45 preferably has an application weight between 1.5 g/m.sup.2 and 5 g/m.sup.2 and comprises acrylates, PVC (=polyvinyl chloride), PUR (=polyurethane) or polyester. The film element 5 of FIG. 8b is a film element in which the layers 44 and 45 can be transferred to a document as transfer ply 40.
(60) FIG. 8c shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41 and a layer 46 having color pigments and/or dissolved dyes. With respect to the layers 41 and 42, reference is made here to the above statements. The layer 46 having the color pigments and/or dissolved dyes is, for example, a layer of carnauba wax, polyurethane, ethylene vinyl acetate, styrene acrylate and color pigments. The layer 46 preferably has an application weight of 4 g/m.sup.2. The film element 5 of FIG. 8c is a film element in which the layer 46 can be transferred to a document as transfer ply 40.
(61) FIG. 8d shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a detachment layer 47 and a layer 46 having color pigments and/or dissolved dyes. With respect to the layers 41, 42, and 46, reference is made here to the above statements. The detachment layer 47 is preferably a wax layer, in particular of candelilla wax and montan acid wax or, alternatively, a layer of strongly filming acrylate. The detachment layer 47 preferably has an application weight of 1.7 g/m.sup.2. The film element 5 of FIG. 8d is a film element in which the layer 46 can be transferred to a document as transfer ply 40.
(62) FIG. 8e shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44 and a layer 46 having color pigments and/or dissolved dyes. With respect to the layers 41, 42, 44 and 46, reference is made here to the above statements. The film element 5 of FIG. 8e is a film element in which the layers 44 and 46 can be transferred to a document as transfer ply 40.
(63) FIG. 8f corresponds to FIG. 8e with the difference that the layer 46 having the color pigments and/or dissolved dyes is applied in the regions 16 and is not applied in the regions 17. The regions 16 and/or the regions 17 can be formed patterned, for example in the form of alphanumeric characters or motifs. It is also possible that the regions 16 and/or the regions 17 are formed in the form of a graphically formed outline, a figural representation, an image, a symbol, a logo, a portrait, a text and the like. The regions 16 and the regions 17 are preferably arranged according to a grid. The resolution limit of the grid can here be greater than the resolution limit of the naked human eye, in particular greater than 300 m.
(64) FIG. 8g corresponds to FIG. 8e with the difference that the layer 46 having the color pigments and/or dissolved dyes has different color pigments and/or dissolved dyes in the regions 18a, 18b and 18c. Thus, the layer 46 can for example be red in color in the region 18a, green in color in the region 18b and yellow in color in the region 18c. It is possible that the regions 18a, 18b and 18c are different colors, which can be represented in a color model such as e.g. the RGB color model or the CMYK color model as a color dot within a color space. Furthermore, it is possible that the regions 18a, 18b and 18c are different colors, for example of the Pantone color system. The regions 18a, 18b and 18c can be formed patterned. The regions 18a, 18b and 18c are preferably formed in the form of strips.
(65) FIG. 8h shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a layer 46 having color pigments and/or dissolved dyes, a metal layer 48 and an adhesive layer 45. With respect to the layers 41, 42, 44 and 45, reference is made here to the above statements. The layer 46 in FIG. 8h preferably has an application weight between 1.0 g/m.sup.2 and 3 g/m.sup.2 and formed semi-transparent. With respect to the further design of the layer 46, reference is made to the above statements. The metal layer 48 is a metal layer of aluminum, preferably with a layer thickness between 10 nm and 100 nm. It is also possible that the metal layer 48 is formed of chromium, gold, copper, silver or an alloy of such metals. The metal layer 48 is preferably vapor-deposited in a vacuum. The film element 5 of FIG. 8h is a film element in which the layers 44, 46, 48 and 45 can be transferred to a document as transfer ply 40.
(66) FIG. 8i corresponds to FIG. 8h with the difference that the metal layer 48 is applied in the regions 16 and is not applied in the regions 17. With respect to the design of the regions 16 and/or the regions 17, reference is made here to the above statements.
(67) FIG. 8j shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a fluorescent varnish layer 49 and an adhesive layer 45. With respect to the layers 41, 42, 44 and 45, reference is made here to the above statements. The fluorescent varnish layer 49 has pigments which, in the case of irradiation with electromagnetic radiation, preferably in the case of irradiation with UV light, emit light from the range of the wavelength range visible to the human eye, in particular in the wavelength range from 380 nm to 780 nm. The application weight of the fluorescent varnish layer 49 is preferably between 0.5 g/m.sup.2 and 2 g/m.sup.2. Furthermore, it is possible that the fluorescent varnish layer 49 is applied in regions. For example, fine-lined security patterns such as for example complex guilloche patterns or other motifs can be formed hereby. The film element 5 of FIG. 8j is a film element in which the layers 44, 49 and 45 can be transferred to a document as transfer ply 40.
(68) FIG. 8k shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a replication varnish layer 50 and an HRI layer 51. With respect to the layers 41, 42, 44 and 45, reference is made here to the above statements. The replication varnish layer 50 preferably has an application weight between 0.2 g/m.sup.2 and 1.5 g/m.sup.2. The replication varnish layer 50 in FIG. 8k is a layer of PMMA and styrene copolymer, which is stamped with a relief structure on the side facing the HRI layer. The relief structure is preferably a diffractive relief structure, in particular selected from the group Kinegram or hologram, zero-order diffraction structure, blazed grating, in particular asymmetrical saw-tooth relief structure, diffraction structure, in particular linear sinusoidal diffraction grating, or crossed sinusoidal diffraction grating or linear single- or multi-step rectangular grating, or crossed single- or multi-step rectangular grating, light-diffracting and/or light-refracting and/or light-focusing micro- or nanostructure, binary or continuous Fresnel lens, binary or continuous Fresnel freeform surface, diffractive or refractive macrostructure, in particular lens structure or microprism structure, mirror surface, mat structure, in particular anisotropic or isotropic mat structure, or combinations of these structures. With respect to the further design of the replication varnish layer 50, reference is made here to the above statement within the context of the replication varnish layer 60b. The HRI layer 51 in Fig. consists, for example, of a vapor-deposited layer of ZnS with a thickness of 20 nm to 120 nm. With respect to the further design of the HRI layer 51, reference is made here to the above statement within the context of the reflective layer 60c. The film element 5 of FIG. 8k is a film element in which the layers 44, 50, 51 and 45 can be transferred to a document as transfer ply 40.
(69) FIG. 8l shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a replication varnish layer 50, a metal layer 48 and an adhesive layer 45. With respect to the layers 41, 42, 44, 45, 48 and 50, reference is made here to the above statements. The film element 5 of FIG. 8l is a film element in which the layers 44, 50, 48 and 45 can be transferred to a document as transfer ply 40.
(70) FIG. 8m corresponds to FIG. 8l with the difference that the metal layer 48 is applied partially in the regions 16 and is not applied in the regions 17.
(71) Furthermore, it is possible that the film element 5 has a further optional varnish layer, not shown in more detail, between the layers 45 and 48, which varnish layer is for example used as an etch resist for structuring a metal layer applied over the whole surface. The optional varnish layer and/or replication varnish layer 50 and/or the transparent protective varnish layer 44 is preferably stained.
(72) Thus, it is for example possible that the replication varnish layer 50 is stained yellow. With respect to the design of the regions 16 and/or the regions 17, reference is made here to the above statements.
(73) FIG. 8n shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a replication varnish layer 50, an HRI layer 51, a metal layer 48 and an adhesive layer 45. In FIG. 8n the metal layer 48 is applied in the regions 16a and not applied in the regions 17a. With respect to the layers 41, 42, 44, 45, 48, 50 and 51, reference is made here to the above statements. With respect to the design of the regions 16a and/or the regions 17a, reference is made here to the above statements in the context of the regions 16 and 17. The film element 5 of FIG. 8n is a film element in which the layers 44, 50, 51, 48 and 45 can be transferred to a document as transfer ply 40.
(74) FIG. 8o shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a transparent protective varnish layer 44, a layer 52 having optically variable pigments and an adhesive layer 45. With respect to the layers 41, 42, 44 and 45, reference is made here to the above statements. By optically variable pigments is here meant pigments which produce a color effect, in particular due to interference effects, which is dependent on the observation angle. In order to produce such a color-change effect with a high degree of brilliance, the pigments must have a similar orientation to each other. Such pigments are, for example, optically variable pigments (OVPs). In addition to the optically variable pigments, layer 52 preferably also has a binder. Such combinations of binders and pigments are, for example, optically variable inks (OVI). OVIs typically have to be printed in significant layer thicknesses in order to produce a recognizable color-change effect with a high degree of brilliance.
(75) The application weight of the layer 52 is preferably between 1.0 g/m.sup.2 and 10 g/m.sup.2. Furthermore, it is possible that the layer 52 is applied in regions, in particular patterned. For example, alphanumeric characters can be formed. It is also possible that the layer 52 is formed as a thin film layer system. A thin film layer system has one or more space layers, the layer thickness of which is selected so that the thin film layer system, by means of interference of the incident light, generates a color shift effect dependent on the observation angle, in particular out of the range of the wavelength range visible to the human eye. Such a thin film layer system is characterized in particular by one or more space layers. The optically effective layer thickness of these space layers, preferably for a specific viewing angle, fulfils the /2 or /4 condition for a wavelength in particular in the range of visible light. The thin film layer system can here consist of a single layer, of a layer system with one or more dielectric layers and one or more metallic layers or of a layer stack with two or more dielectric layers. The film element 5 of FIG. 8o is a film element in which the layers 44, 52 and 45 can be transferred to a document as transfer ply 40.
(76) FIG. 8p shows a film element 5 which has a heat-resistant layer 42, a carrier layer 41, a replication varnish layer 50, a detachment layer 47, a transparent protective varnish layer 44 and a layer 46 having color pigments and/or dissolved dyes. The film element 5 of FIG. 8p is a film element in which the layers 44 and 46 can be transferred to a document as transfer ply 40. A relief structure is stamped into the replication varnish layer 50 at least in regions. The detachment layer is preferably a thin wax layer, the application weight of which is 0.01 g/m.sup.2. During the application of the layers 44 and 46 to a document, a relief structure that is inverted with respect to the relief structure of the replication varnish layer 50 is molded into the transparent protective varnish layer 44. During the application, the transparent protective varnish layer 44, together with the layer 46, is separated from the detachment layer 47. The negative form of the relief structure molded into the replication varnish layer 50 is hereby molded onto the transparent protective varnish layer 44 and the layers 44 and 46 are simultaneously transferred to a document. With respect to the further design of the layers 41, 42, 44, 46, 47 and 50, reference is made here to the above statements.
(77) FIG. 9 to FIG. 12 show schematic top views and sectional representations of design variants of a document 1.
(78) FIG. 9 thus shows a document 1 with a thermographic substrate 2, which has second layers in the region 13. In the region 13a, the second layers are formed opaque and further have the security features 61b. The security features 61b are, for example, a zero-order diffraction structure. The region 13b is formed transparent and comprises the security elements 61a, which are formed in the shape of a star as shown in FIG. 9 and form a volume hologram. The region 13 extends over the entire width of the document 1, as shown in FIG. 9. A first item of information 20a is further introduced into the thermographic substrate 2 by activation of the color change 15 in the thermographic substrate 2. The document 1 further has first layers which represent a second item of information 21a. The document 1 is, for example, a ticket. With respect to the introduction of the first item of information 20a into the thermographic substrate 2 of the document 1 and the application of the first layers to the document 1 to represent the second item of information 21a, reference is made here to the above statements.
(79) FIG. 10 shows a document 1 with a thermographic substrate 2. In regions, the thermographic substrate 2 has the second layers 60, which comprise the layers 60a, 60b, 60c and 60d. With respect to the design of the layers 60a, 60b, 60c and 60d, reference is made here to the above statements. A color change 15 is activated in the regions 10s in the thermographic substrate 2, which appears black to an observer 70. Furthermore, the transfer ply 40a is applied to the thermographic substrate 2 in the regions 10s. In the region 10s, the transfer ply 40a is formed as a protective varnish layer and transparent. The transfer ply 40a is applied to the thermographic substrate 2 in the regions 11s, which have red color pigments and are opaque. A color change 15a is activated in the region 10t in the thermographic substrate 2, which appears colored magenta to an observer 70. The thermosensitive layer 31 in FIG. 10 has two different color changes 15, 15a depending on the temperature effect. Thus, the color change 15 of the thermosensitive layer 31 in FIG. 10 is activated at a temperature of approximately 100 C. in the regions 10s and the color change 15a is already activated at a temperature of approximately 90 C. in the region 10t. Furthermore, the transfer ply 40a is applied to the thermographic substrate 2 in the regions 10t and 11 t, which are stained green and are formed transparent.
(80) FIG. 11 shows a document 1 with a thermographic substrate 2. A first item of information 20a is introduced into the thermographic substrate 2. The first item of information 20a is introduced by activation of the color change in the thermographic substrate 2. The document 1 further has first layers in the form of a fine-lined figure for representation of a second item of information 21a. The document 1 further has a transfer ply in the form of a barcode for representation of a second item of information 21b. The document 1 is, for example, a travel ticket. With respect to the introduction of the first item of information 20a into the thermographic substrate 2 of the document 1 and the application of the transfer ply for representation of the second items of information 21a and 21b to the document 1, reference is made here to the above statements.
(81) FIG. 12 shows a document 1 with a thermographic substrate 2. In the regions 10 and 11u, the document 1 has the transfer ply 40a which comprises the layers 44, 50, 48 and 45. With respect to the design of the layers 44, 50, 48 and 45, reference is made here to the above statements. A color change 15 is activated in the region 10u in the thermographic substrate 2, which appears black to an observer 70. The layer 48 is present only in the regions 19. The regions 19 are arranged in the form of a grid with grid widths of 350 m, with the result that an observer 70 can recognize the color change 15 activated in the region 10u. The color change 15 is not activated in the thermographic substrate 2 in the region 11u. With respect to the layers 30, 31, 32, 33 of the thermographic substrate 2, reference is made here to the above statements. The layer 35 is a layer which has pigments which, in the case of irradiation with electromagnetic radiation, preferably in the case of irradiation with UV and/or IR light, emit light from the range of the wavelength range visible to the human eye, in particular in the wavelength range from 380 nm to 780 nm. It is possible that the layer 35 is applied, in particular patterned, in regions.
LIST OF REFERENCE NUMBERS
(82) 1 document 2 thermographic substrate 5 film element 6 thermal print head 6h heating elements 10a, 10b, 10c, 10d, 10e, first region 10f, 10g, 10h, 10i, 10j, 10k, 101, 10m, 10n, 10o, 10p, 10r, 10s, 10t, 10u 11a, 11b, 11c, 11q, 11 r, 11s, 11t, 11u second region 12 recording range 13, 13a, 13b, 14 regions 15 color change 16, 17, 18a, 18b, 18c, 19 partial regions 20a, 20b, 20c, 20d, 20e, first item of information 20f 21a, 21b second item of information 25, 26, 27 co-ordinate axes x, y, z 28 feed direction 30 base layer 31 thermosensitive layer 32 protective layer 33 intermediate layer 34, 35 third layers 40 transfer ply 40a applied transfer ply 40e removed transfer ply 41 carrier layer 42 heat-resistant layer 43 sliding layer 44 transparent protective varnish layer 45 adhesive layer 46 layer having color pigments and/or dissolved dyes 47 detachment layer 48 metal layer 49 fluorescent varnish 50 replication varnish layer 51 HRI layer 52 layer having optically variable pigments 60 second layers 60a protective varnish layer 60b replication varnish layer 60c reflective layer 60d bonding layer 61 decorative layer 62a, 62b security features 70 observer
