SURFACE SECURITY ELEMENT WITH OPTICAL SECURITY FEATURES

Description

FIELD OF THE INVENTION

[0001] The invention relates to a starting material for a value document, with a security element in the form of a strip for use as a security thread in value documents, such as banknotes, wherein the security element has a first reflectance for visible light on a first surface, wherein the first surface of the security element is provided in at least one first longitudinal section with a cover layer which has a second reflectance for visible light which is greater than the first reflectance of the first surface, while the first surface is not provided with such a cover layer in at least one second longitudinal section, and wherein at least one first longitudinal section of the security element which is provided with a cover layer is at least partially covered by a section of the starting material, while at least one second longitudinal section of the security element which is not provided with a cover layer is not covered by a section of the starting material or such a second longitudinal section is only covered by a further section of the starting material with a smaller thickness than that section of the starting material which has at least one first,covers the longitudinal section of the security element provided with a covering layer.

[0002] The invention also encompasses a value document comprising this starting material. The security element according to the invention is particularly suitable as a security thread for value documents with a window security thread. STATE OF THE ART

[0003] A security thread is typically a 0.5 mm to 8 mm wide strip, made of plastic, for example, which is inserted into the source material of the security document, usually paper, during its production. With a window security thread, the security thread is exposed in sections by reducing the paper thickness above the security thread, or by removing any paper at all from this section of the security thread. The security thread can also be provided with patterns, numbers, or letters, a lasered marking, or other optical or invisible properties, so that this information is visible in the window of the source material or the finished security document.

[0004] EP 2420391 A1 discloses a security thread with a metallic layer arranged only in sections. EP 2420391 A1 does not contain any information on the relative arrangement of individual sections of the security thread and windows.

[0005] WO 2004 / 049353 A2 discloses the preamble of claim 1 and relates to a security thread comprising a carrier film and a cover layer applied to the carrier film. The cover layer has recesses containing a printed image in register. The cover layer can comprise a metal coating and thus have a higher degree of reflection than, for example, the printed image. The cover layer is present over the entire length of the security thread.

[0006] WO 2018 / 145813 A1 relates to a value document with a window security thread, which is visible on a surface of the substrate in a sequence of window regions and concealed in a sequence of web regions located between the window regions. The security thread, with its sequence of check regions and free regions, is embedded in the substrate in a manner registered with the sequence of window regions and web regions, such that the security features of the check regions are visible in reflected light in the window regions, and the free regions are concealed in the web regions. The free regions are designed without any security features and are formed, for example, by the bare carrier film of the security thread. WO 2018 / 145813 A1 does not disclose a cover layer in the free region of the security thread.

[0007] With window security threads, it is desirable that they be visible only in the window, where the paper thickness is reduced or absent altogether. In the so-called bridge area, where they run through the paper and are thus covered by a layer of paper, they should be as invisible as possible. Many security threads now have a continuous metallic surface and are therefore barely visible in reflection, even in the bridge area.

[0008] However, if a window security thread has a low reflectance, the paper layer in the bridge area is often not thick enough to conceal the window security thread when viewed in incident light. If the window security thread remains visible through the paper layer in the bridge area, this impairs the visual appearance of the valuable document. DESCRIPTION OF THE INVENTION

[0009] An object of the invention is therefore to provide a starting material with a security element in the form of a strip for use as a security thread in value documents, which, despite a low degree of reflection, i.e., for example, despite incomplete surface metallization, is less optically recognizable in incident light in the bridge area of ​​a value document.

[0010] This object is achieved by a starting material according to claim 1. It is provided that the length of the first longitudinal section of the security element, which is provided with a cover layer, corresponds to the length of the section of the starting material which covers this first longitudinal section, wherein the first longitudinal section does not protrude significantly beyond this bridge region or essentially completely traverses it, while the length of the second longitudinal section of the security element, which is not provided with a cover layer, corresponds to the length of a window of the starting material which either forms a continuous recess in the starting material which is arranged above the security element, or is formed by a further section of the starting material with a smaller thickness than that section of the starting material which covers the first longitudinal section of the security element provided with a cover layer.

[0011] The cover layer increases the reflectivity of the strip in this longitudinal section, so that this longitudinal section appears brighter in reflected light. The length of a coated longitudinal section is dimensioned, for example, so that it corresponds to the length of a bridging area of ​​the source material or value document into which the strip is to be integrated. This means that the strip is barely visible or not visible at all in the bridging area, depending on the thickness of the section of the source material or value document arranged above the cover layer, i.e. depending on the thickness of a paper layer arranged above the cover layer in the bridging area, and depending on the reflectance of the cover layer. If there are several bridging areas per value document, the distance between the coated longitudinal sections must also be adjusted to the distances between the bridging areas.The non-coated longitudinal section(s) still show the desired first surface with any information contained therein and appear in a window of the valuable document after the strip has been embedded in the source material, usually paper, for the valuable document.

[0012] The section of the starting material that covers the first, coated longitudinal section of the security element is referred to as the bridge region. The window of the starting material or value document, in which the second, uncoated longitudinal section of the security element is to be visible, can firstly be formed in such a way that it is not covered by any section of the starting material, i.e. the window forms a continuous recess in the starting material that is arranged above the security element. Secondly, the window can be formed in such a way that, although the second, uncoated longitudinal section of the security element is also covered by a section of the starting material, this further section has a smaller thickness than the bridge region, so that the security element is in any case more visible in the window than in the bridge region.

[0013] In other words, if the length of a first longitudinal section of the security element provided with a covering layer corresponds to the length of the section of the starting material covering this first longitudinal section, the bridge region and the first, coated longitudinal section of the security element are of equal length, viewed in the longitudinal direction of the security element. In particular, the second, uncoated longitudinal section will then correspond to the length of the window.

[0014] It is also conceivable for the length of a coated longitudinal section to be greater than the length of a corresponding bridging region of the source material or value document into which the strip is to be integrated. As a result, a longitudinal section with a cover layer emerges from the source material or value document, viewed in the longitudinal direction of the strip, before and / or after the bridging region and becomes visible. This visible longitudinal section with a cover layer can again represent a security feature, as it creates an area with a third optical impression (in addition to the bridging region, where the cover layer is covered by a section of the source material or value document, and in addition to the visible section of the strip that is neither covered by a cover layer nor by a section of the source material or value document (or only by a correspondingly thinner further section of the source material or value document).valuable document) and thus forms the visible security thread).

[0015] Accordingly, the length of a first longitudinal section of the security element provided with a covering layer corresponds to the length of the section of the starting material that covers this first longitudinal section. In particular, it can be provided that the covering layer is visible over less than 20%, in particular over less than 10%, of the diameter of a window formed by a recess in the starting material or through another section of the starting material with a smaller thickness than that section of the starting material that covers at least a first longitudinal section of the security element provided with a covering layer.

[0016] It is also conceivable for the length of a coated longitudinal section to be shorter than the length of a corresponding bridging region of the source material or value document into which the strip is to be integrated. As a result, in the source material or value document, viewed in the longitudinal direction of the strip, at the beginning and / or end of the bridging region there is a longitudinal section without a cover layer below the bridging region and this is more visible than the longitudinal section of the strip that is covered with a cover layer. This more visible longitudinal section without a cover layer can again represent a security feature, as it creates an area with a third optical impression (in addition to the remaining bridging region where a cover layer is present, and in addition to the visible section of the strip that is neither covered by a cover layer nor by a section of the source material or value document).valuable document (or only by a correspondingly thinner further section of the original material or valuable document) and thus forms the visible security thread).

[0017] Accordingly, the length of a first longitudinal section of the security element provided with a covering layer would be smaller than the length of the corresponding section of the starting material covering this first longitudinal section.

[0018] The reflectance is the ratio between the reflected and incident light intensity. The reflectance indicates what percentage of the luminous flux falling on a surface is reflected.

[0019] The source material for the security document will usually be in sheets or rolls. The security element will also usually be in the form of a continuous strip or at least as a strip for several similar security documents. The individual similar security documents are then produced, for example, by trimming the source material provided with the strip. In this respect, it can be provided that one or more first longitudinal sections of the security element, which are provided with a cover layer, are repeated periodically in the longitudinal direction of the security element. Care must be taken to ensure that the spacing between the first longitudinal sections is such that these first longitudinal sections each lie in the bridge area. It must therefore be ensured that the strip is inserted into the source material for the security document (or into the security document) with essentially exact register.Due to production fluctuations, it may happen that the first longitudinal sections provided with the covering layer unintentionally protrude into the window to a minor extent, which would nevertheless fall within the scope of the invention. It is considered insignificant if the covering layer is visible over less than 20%, in particular over less than 10%, of the diameter of the window.

[0020] A particularly good result is achieved if the first surface of the security element is completely covered with a cover layer in at least a first longitudinal section. Thus, the entire width of the strip in this longitudinal section is covered with a cover layer. The cover layer then has the shape of a rectangle with a width (or length) corresponding to the width of the strip and a length (or width) corresponding to the length of the first longitudinal section.

[0021] Alternatively, it can be provided that the first surface of the security element is partially provided with a covering layer in at least a first longitudinal section, with recesses in the covering layer forming characters or patterns. The covering layer also fulfills its function of making the strip as such invisible or barely visible later in the bridge area of ​​the starting material or value document. Although the recesses in the covering layer make the uncoated surface of the strip visible again, the viewer sees the characters or patterns and not a continuous dark stripe. The characters or patterns produced in this way serve as additional security features.

[0022] In a further embodiment of the invention, at least one character or pattern is applied to the cover layer of the security element, which character or pattern has a third reflectance for visible light that is lower than the second reflectance of the cover layer. Simply put, characters or patterns that appear dark relative to the cover layer are applied to the relatively light-appearing cover layer. These characters or patterns then shine through the section of the source material or value document in the bridge region of the source material or value document and serve as additional security features. These characters or patterns can, for example, be printed on the cover layer.

[0023] It would also be conceivable for the second surface of the security element, i.e. the other side of the strip, to also have a low degree of reflection and to also shine through as a dark stripe in a bridge region on the other side of the starting material or value document. In this case, it can be provided that the second surface of the security element has a first degree of reflection for visible light and is provided in at least a first longitudinal section with a cover layer which has a second degree of reflection for visible light that is greater than the first degree of reflection of the second surface, while the second surface is not provided with such a cover layer in at least a second longitudinal section. In this way, the second side of the strip could also be used as a window security thread.The valuable document would then also have to have windows and bridge areas on the second side.

[0024] The cover layer on the second surface of the security element can be formed in the same embodiments as the cover layer on the first surface: one or more first longitudinal sections provided with a cover layer can repeat periodically in the longitudinal direction of the security element. The position, length, and periodicity of these first longitudinal sections can, but do not have to, match those on the first surface. Furthermore, the second surface can be completely provided with a cover layer in at least one first longitudinal section. Furthermore, the second surface can be partially provided with a cover layer in at least one first longitudinal section, with recesses in the cover layer forming characters or patterns.Furthermore, at least one character or pattern can be applied to the cover layer, which has a third reflectance for visible light that is lower than the second reflectance of the cover layer. The same applies to the arrangement of the bridge regions and windows of the starting material on the second surface of the security element as described above for the first surface of the security element.

[0025] In one embodiment of the invention, the cover layer of the security element comprises a metallic layer. In particular, the cover layer can be a metallic layer. A metallic layer can be a pure metal layer or a layer containing metallic clusters. The metallic layer preferably comprises at least one metal from the group consisting of aluminum, gold, titanium, vanadium, cobalt, tungsten, niobium, iron, molybdenum, palladium, platinum, chromium, silver, copper, nickel, tantalum, tin, and / or their alloys, for example gold / palladium, copper / nickel, copper / aluminum, or chromium / nickel.

[0026] In one embodiment of the invention, the cover layer of the security element contains a metallic effect ink. In particular, the cover layer can be a layer of metallic effect ink. Metallic effect inks are paints or varnishes based, for example, on metallic pigments or on doped or undoped semiconductor pigments, preferably in the form of platelets. Examples of such semiconductor pigments are silicon, gallium, or tellurium pigments, which have a metallic luster. Examples of metallic pigments are pigments containing aluminum, gold, titanium, vanadium, cobalt, tungsten, niobium, iron, molybdenum, palladium, platinum, chromium, silver, copper, nickel, tantalum, tin, and / or their alloys. These pigments and the paint or varnish produced using these pigments have a metallic luster and therefore appear visually as a metallically shiny or reflective coating.Metallic effect paints also include paints or varnishes based on mica, coated with titanium oxide TiO or iron Fe.

[0027] In one embodiment of the invention, the cover layer of the security element contains a printed ink. In particular, the cover layer can be a layer of printed ink. In this case, ink is printed onto the first longitudinal section(s) of the first surface of the security element. Appropriate selection of the color pigments ensures that they have a correspondingly high degree of reflection.

[0028] In one embodiment of the invention, the cover layer of the security element contains white pigments. In particular, the cover layer can be a layer made of a material containing white pigments. Known white pigments include TiO2 or ZnS.

[0029] In principle, several materials of the aforementioned embodiments can be combined for the cover layer, for example, by stacking several layers of the different materials on top of each other to form the cover layer. Alternatively, several materials are first mixed and then applied as a single layer, for example, by mixing white pigments into other, subsequently printed colors. Alternatively, several materials of the aforementioned embodiments are arranged side by side to form the cover layer.

[0030] The source material, usually paper, for the security document is usually produced in the form of sheets or rolls. The security element is also usually present as a continuous strip or at least as a strip for several similar security documents. The strip is then embedded, for example, between two layers of the source material. The strip is placed on a base layer, which is in particular a thicker one, and covered with a cover layer, which is in particular a thinner one, whereby this cover layer, for example a layer of paper, has an even smaller thickness or a recess in a window. The two layers are joined together to form the source material, and the strip forming the security element is embedded in the source material. The individual similar security documents are then produced, for example, by trimming the source material with the strip.The first longitudinal sections, which are provided with a cover layer, repeat periodically in the longitudinal direction of the security element, corresponding to the dimensions of the value document in the direction of the security element. Thus, these first longitudinal sections each lie in a bridge area, while the second longitudinal sections each lie in a window.

[0031] After embedding the security element, the source material can be printed and provided with additional security elements. Individual, identical security documents are then produced by cutting the source material.

[0032] The invention also relates to a value document with a security element according to the invention, i.e. a value document that comprises at least one starting material according to the invention, in particular is produced from a starting material according to the invention. Consequently, it is provided that at least a first longitudinal section of the security element, which is provided with a cover layer, is at least partially covered by a section of the value document, while at least a second longitudinal section of the security element, which is not provided with a cover layer, is not covered by a section of the value document, and that at least a first longitudinal section of the security element, which is provided with a cover layer, is at least partially covered by a section of the starting material, while at least a second longitudinal section of the security element, which is not provided with a cover layer,is not covered by a portion of the starting material or such a second longitudinal portion is covered only by a further portion of the starting material with a smaller thickness than that portion of the starting material which covers at least a first longitudinal portion of the security element provided with a covering layer.

[0033] The length of a longitudinal section coated with a cover layer is dimensioned, for example, to correspond to the length of a bridge area of ​​the value document (or source material) into which the strip is integrated. As a result, the coated longitudinal section is completely covered by the section of the value document (or source material) forming the bridge area, and the strip is barely or not at all visible in the bridge area, depending on the thickness of the section of the value document (or source material) arranged above the cover layer (e.g., depending on the thickness of a paper layer arranged above the cover layer in the bridge area), and depending on the reflectivity of the cover layer.If multiple bridge areas are present per value document, the spacing of the coated longitudinal sections should preferably be adjusted to the spacing of the bridge areas, so that all other coated longitudinal sections are also located in a bridge area and do not extend significantly beyond this bridge area in the longitudinal direction of the strip or essentially extend through it. The uncoated longitudinal section(s) still display the desired first surface with any information contained therein and appear in a window of the value document.

[0034] It is also conceivable that the length of a coated longitudinal section is greater than the length of an associated bridging region of the value document (or source material), i.e. greater than the length of a section of the value document (or source material) that covers this first longitudinal section. As a result, in the value document (or source material), viewed in the longitudinal direction of the strip, a longitudinal section with a cover layer comes to the surface before and / or after the bridging region and becomes visible in the window of the value document (or source material). This visible longitudinal section with a cover layer can again represent a security feature, as it creates an area with a third optical impression (in addition to the bridging region, where the cover layer is covered by a section of the value document, and in addition to the visible section of the strip that is neither covered by a cover layer nor by a section of the value document or source material).source material (or only by a correspondingly thinner further section of the source material or value document) and thus forms the security thread visible in the window).

[0035] It is also conceivable that the length of a coated longitudinal section is shorter than the length of a corresponding bridging region of the value document (or source material). As a result, in the value document (or source material), viewed in the longitudinal direction of the strip, at the beginning and / or end of the bridging region there is a longitudinal section without a cover layer below the bridging region and this is more visible than the longitudinal section of the strip that is covered with a cover layer. This more visible longitudinal section without a cover layer can again represent a security feature, as it creates an area with a third optical impression (in addition to the remaining bridging region where a cover layer is present, and in addition to the visible section of the strip that is neither covered by a cover layer nor by a section of the value document or source material (or only by a correspondingly thinner further section of the source material orvaluable document) and thus forms the security thread visible in the window).

[0036] The strip used as a security element generally has a thickness of 5-700 µm, preferably 5-200 µm, particularly preferably 5-50 µm.Examples of materials used include transparent carrier films, preferably flexible plastic films, for example made of polyimide (PI), polypropylene (PP), monoaxially oriented polypropylene (MOPP), biaxially oriented polypropylene (BOPP), polyethylene (PE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherketone (PEK), polyethyleneimide (PEI), polysulfone (PSU), polyaryletherketone (PAEK), polyethylene naphthalate (PEN), liquid crystalline polymers (LCP), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), cycloolefin copolymers (COC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), ethylenetetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), Ethylene-tetrafluoroethylene-hexafluoropropylene fluoroterpolymer (EFEP), copolymers of the aforementioned materials and / or mixtures of several of the aforementioned materials.The material can be transparent, translucent, semi-opaque or opaque.

[0037] The security element containing the cover layer can be surface-treated, coated, or laminated, for example coated or laminated with plastics, or varnished, in particular on the first surface, which in the value document can be partially located on the surface of the value document, in order to be protected against mechanical, physical, and / or chemical influences. A protective varnish layer can, for example, be based on nitrocellulose, acrylates and their copolymers, polyamides and their copolymers, polyvinyl chlorides and their copolymers, or consist of a cross-linking varnish. Furthermore, the security element can be provided on one or both sides with an adhesive layer to enable fixation in the starting material for the value document. This adhesive layer can be designed either in the form of a heat-seal, cold-seal, or self-adhesive coating. SHORT DESCRIPTION OF THE CHARACTERS

[0038] The invention will now be explained in more detail with reference to schematic figures which illustrate exemplary embodiments. Fig. 1 supervision of a security document in accordance with the state of the art, Fig. 2 a view of a security document according to the invention, Fig. 3 a cross-section of the value document Fig. 2 according to section line AA. WAYS OF IMPLEMENTING THE INVENTION

[0039] Fig. 1 shows a top view of a section of a value document 1, here a banknote. Embedded in this section is a security element 2 in the form of a security thread, running vertically here, forming a window security thread. The security element 2 is directed towards the viewer with its first surface, which is not metallized, and is exposed in two windows 3, here rectangular, and is therefore not covered by the paper of the value document 1, or is covered to a lesser extent than in the bridge areas 4. In three bridge areas 4, the security element 2 lies beneath a layer of paper, but is still recognizable as a dark area.

[0040] In order to provide the security element 2 with the inventive feature of the cover layer 11, before embedding the security element 2 in the value document 1, a cover layer 11 is applied in those longitudinal regions of the security element 2 that correspond to the bridge regions 4, which cover layer appears brighter than the surface of the security element 2 in the window 3. As a result, the security element 2 is Fig. 2 now less or no longer visible in the bridge areas 4.

[0041] Fig. 3 shows a cross-section through the value document 1 from Fig. 2 according to section line AA. The longitudinal direction of the security element 2 runs horizontally in the plane of the drawing, the light falls from above onto the value document 1, and the viewer sees the value document 1 from above. The individual layers of the value document 1 and the security element 2 can be seen.

[0042] Only a portion of the bottom layer of the security document 1 is shown here. The bottom layer is the paper 5, from which the security document 1 is mainly made, and would be correspondingly thicker than the other layers. The security element 2 is applied to the paper 5, here consisting of the following layers: a layer of heat-sealing varnish 6, for bonding the security element 2 to the paper 5, followed by a primer 7, which serves to promote adhesion. The primer 7 is followed by the actual carrier material of the security element 2, here a layer of PET 8. An absorbent black lacquer layer 9 is applied to the PET 8 carrier material, which in turn carries a layer 10, which in this case creates a color-shift effect. This color-shift effect is intended to be visible in the windows 3.To prevent the security element with its layer 10 from shining through the bridge areas 4, which consist of paper 5, and appearing dark, a cover layer 11 is applied there. The security element 2 is then bonded via a further layer of heat-sealing varnish 6 to a cover layer of paper 5, which forms the bridge areas 4 as a paper layer.

[0043] Of course, instead of layer 10, one or more other poorly reflecting layers can also be provided for a color-shift effect, particularly those that convey information. Depending on the structure, neighboring layers, such as the absorbing black lacquer layer 9, can then be omitted or replaced by other layers.

[0044] The optical impression of the cover layer 11 can be further changed if the cover layer 11 forms recesses in the form of characters or patterns, or if at least one character or pattern is applied to the cover layer 11.

[0045] The cover layer 11 could be Fig. 3 now be made shorter at least in one bridge area 4 on the left and / or right, so that the cover layer 11 would then be shorter (seen from left to right) than the bridge area 4. This would achieve three different optical effects with the security element 2: The first optical impression is created in the bridge area, where the cover layer 11 is covered by a section of the paper 5. The second optical impression is created in the area of ​​the window 3, where the security element 2 is covered neither by a cover layer 11 nor by a section of the paper 5. The third optical impression is created in the bridge area 4, where there is no longer a cover layer, i.e. the layer 10 for a color shift effect would be visible through the section of the paper 5.

[0046] The cover layer 11 could be Fig. 3alternatively or additionally, at least in one bridge area 4 on the left and / or right, the cover layer 11 could be made longer, so that the cover layer 11 would then be longer (seen from left to right) than the bridge area 4. This would achieve three different optical effects with the security element 2: The first optical impression is created in the bridge area, where the cover layer 11 is covered by a section of the paper 5. The second optical impression is created in the area of ​​the window 3, where the security element 2 is covered neither by a cover layer 11 nor by a section of the paper 5. The third optical impression is created in the window 3, more precisely on the left and right at the edge of the window 3, where a cover layer 11 is now also present.The third optical impression can be further changed if the cover layer 11 forms recesses in the form of characters or patterns, or if at least one character or pattern is applied to the cover layer 11. LIST OF REFERENCE SYMBOLS

[0047] 1Value document (banknote) 2Security element 3Window 4Bridge area 5Paper 6Heat seal varnish 7Primer 8Carrier material PET 9Absorbent black varnish layer 10Layer for color shift effect 11Cover layer

Claims

1. A starting material for a value document (1), comprising a security element (2) in the form of a strip for use as security threads in value documents (1), such as banknotes, wherein the security element (2) has a first degree of reflection for visible light on a first surface, wherein the first surface of the security element (2) is provided with a cover layer (11) in at least one first longitudinal portion, said cover layer having a second degree of reflection for visible light which is greater than the first degree of reflection of the first surface, while the first surface is not provided with such a cover layer (11) in at least one second longitudinal portion, and wherein at least one first longitudinal portion of the security element (2) which is provided with a cover layer (11) is covered by a portion of the starting material at least in some regions while at least a second longitudinal portion of the security element (2) which is not provided with a cover layer (11) is not covered by a portion of the starting material or such a second longitudinal portion is only covered by another portion of the starting material with a smaller thickness than the portion of the starting material which covers at least one first longitudinal portion of the security element provided with a cover layer (11), characterised in that the length of the first longitudinal portion of the security element (2) which is provided with a cover layer (11) corresponds to the length of the portion of the starting material which covers this first longitudinal portion, wherein the first longitudinal portion does not project substantially beyond this bridge region (4) or runs substantially entirely through it, while the length of the second longitudinal portion of the security element (2) which is not provided with a cover layer (11) corresponds to the length of a window (3) of the starting material, which either forms in the starting material a continuous cutout, which is arranged above the security element (2), or is formed by a further portion of the starting material with a lower thickness than the portion of the starting material which covers the first longitudinal portion of the security element provided with a cover layer (11).

2. The starting material according to claim 1, characterised in that one or more first longitudinal portions of the security element (2) which are provided with a cover layer (11) repeat periodically in the longitudinal direction of the security element (2).

3. The starting material according to claim 1 or 2, characterised in that the first surface of the security element (2) is provided completely in at least one first longitudinal portion with a cover layer (11).

4. The starting material according to claim 1 or 2, characterised in that the first surface of the security element (2) is provided in at least a first longitudinal portion partially with a cover layer (11), wherein cutouts in the cover layer (11) form symbols or patterns.

5. The starting material according to any one of the preceding claims, characterised in that at least one symbol or pattern is applied to the cover layer (11) of the security element (2) and has a third degree of reflection for visible light that is smaller than the second degree of reflection of the cover layer (11).

6. The starting material according to any one of the preceding claims, characterised in that the second surface of the security element (2) has a first degree of reflection for visible light and is provided in at least a first longitudinal portion with a cover layer (11) which has a second degree of reflection for visible light which is greater than the first degree of reflection of the second surface, while the second surface is not provided with such a cover layer (11) in at least a second longitudinal portion.

7. The starting material according to claim 6, characterised in that the cover layer (11) is formed on the second surface of the security element (2) in accordance with any one of claims 3 to 5.

8. The starting material according to any one of the preceding claims, characterised in that the cover layer (11) of the security element (2) comprises a metal layer.

9. The starting material according to any one of claims 1 to 8, characterised in that the cover layer (11) of the security element (2) contains a metal effect colour.

10. The starting material according to any one of claims 1 to 9, characterised in that the cover layer (11) of the security element (2) contains a printed colour.

11. The starting material according to any one of claims 1 to 10, characterised in that the cover layer (11) of the security element (2) contains white pigments.

12. A value document (1) with a security element (2), comprising at least one starting material according to any one of claims 1 to 11.