CN110167762A - Security element with reflection colour filter characteristic - Google Patents

Abstract

The present invention relates to a kind of for manufacturing the Security element (2) with reflection colour filter characteristic of the valuable documents such as banknote (1), check, the Security element (2) has the contour structure (6) for having raised (7) above substrate surface (10), and has above metal.Raised (7) have the clad can (8) for being parallel to substrate surface (10), and, when from cross section, it is each protrusion (7) have at least one step, and relative on substrate surface (10) position and/or expanded range be distributed in a manner of quasi-static.Step height (t) is between 100 nanometers and 350 nanometers.

Description

Security element with reflection colour filter characteristic

Technical field

The anti-fake of colour filter characteristic is reflected for manufacturing having for the valuable documents such as banknote, check the present invention relates to a kind of Element, the Security element have the contour structure for having elevated regions on substrate and metal.

The invention further relates to a kind of for manufacturing the manufacturing method of the Security element of the valuable documents such as banknote, check, Wherein, the contour structure for there are elevated regions on substrate and metal is produced.

Background technique

Sub-wave length grating can be used for generating the color effect with very delicate spatial resolution.Generic patent document DE 102011101635 A1 disclose a kind of two-dimensional and periodic nanostructure, which provides reflection and transmission color.In this situation Under, it is a kind of stamping structure, and one layer of aluminium layer has only been deposited on it.One the disadvantage is that, this nanostructure must be can mould System, to realize ratio of defects is low and structure adhesiveness is high continuous manufacture.It is logical for realizing the known nanostructured of color effect Often with having the aspect ratio greater than 1 and period less than 300 nanometers.For these structures, the moulding process of zero defect duplication is realized It is a problem.

Other structures are also disclosed in the prior art, i.e., so-called A Ziteke structure is (referring to US 20080309996 A1；J.J.Cowan, the " (surface A Ziteke Aztec surface-relief volume diffractive structure Embossment volume diffraction structure) ", JOSA A, 7.8 (1990): 1529-1544).These step-like embossment structures are arranged so that phase The optical path of adjacent step forms path difference and interferes.This path difference leads to the mutually long superposition and the phase of other wavelength of specific wavelength Disappear superposition.The interference of light in these documents is used to form volume hologram.Further, it is known that can also shape in this way At phase hologram (referring to 4888260 B1 of US；E., Hasman et al., " Efficient multilevel phase holograms for CO₂Lasers (the high-efficiency multi-stage phase hologram of carbon dioxide laser) ", optics letter, 16.6 (1991): 423-425).In addition, also once attempted with the blue of this structure replication indigo plant butterfly (referring to J.J., Cowan, " Advances in holographic replication with the Aztec structure (uses A Ziteke structure Carry out the progress of holographic copy) ", Proc., Internat.Conf., holography journal, (2006)；S., Kinoshita et al., " Physics of structural colors (structural color physics) ", Proceedings in Physics report, 71.7 (2008): 076401).WO 2015188908A1 illustrates a kind of for manufacturing the Security element with the structural color unrelated with angle Method.Color is formed by the microballoon for having cated random alignment.The document (" Color- of A.Yetisen et al. Selective 2.5D Holograms on Large-Area Flexible Substrates for Sensing and Multilevel Security is (holographic with the color preference 2.5D on the large area flexible substrate of Multi-stage antiforging for sensing Figure) ", advanced optical material, 4.10 (2016): 1589-1600) to illustrate color preference hologram be based on can pass through pressure Impression method copies to the application of the anti-counterfeiting characteristic of the step-like structure on flexible parent metal.

Summary of the invention

It is an object of the invention to develop a kind of stamping structure for being easier to manufacture and still show excellent color effect.

The present invention limits in claim 1,6 and 7.

The Security element provides reflection colour filter characteristic, and this reflection colour filter characteristic can be used for manufacturing such as banknote, check Equal valuable documents, to prevent from forging.It has the contour structure for having elevated regions in substrate.The upper surface of the contour structure is gold Belong to, entire contour structure is also possible to metal.In terms of cross section, each elevated regions are at least the form of separate unit rank.It Step height be at least consistent in local level, and between 100 nanometers and 350 nanometers.Elevated regions are in base Quasi- statistically opsition dependent and/or range distribution on bottom.In an advantageous modification, elevated regions are multi-step forms , and there are two to two ten steps.Separate unit rank or the multi-step characteristic of elevated regions can be told, because elevated regions Clad can is parallel relative to substrate.In the case where multi-step construction, the tyre tread of the clad can of step herein and conventional stair It is corresponding.The step at the highest level of elevated regions is parallel also relative to substrate.

Term " separate unit rank " describes the elevated regions only from substrate to single clad can with a step.Therefore, step Quantity is identical as the series of clad can.In the case where separate unit rank elevated regions, only has a clad can in level-one.It is convex in multi-step In the case where playing region, there are multiple clad cans, wherein the distance between continuous clad can in an elevated regions is always identical 's.In other words, the step height in elevated regions is constant.

Elevated regions are arranged in relative to the aperiodicity (especially quasi- statistical) of position and/or range in substrate Surprising light tone is generated in reflected light.

Elevated regions are at least consistent in local level, such as step height and optionally for platform It is consistent for order amount.The range of elevated regions is not necessarily the same herein.It has been proved that step height influences reflection Color.The spectral width of numbers of steps influence color reflective.The locality of step height (and optional numbers of steps) changes Allow to generate the region that different colours reflect in Security element, to realize the coding of pattern.

Security element can be generated by simple moulding process.Particularly advantageous here is contour structure is by transparent material It is formed, is then coated with metal layer to generate metal surface.Alternatively, contour structure is also possible to directly be formed in metal material , it means that it is not only metal on the surface.

In order to realize preferred colour filter characteristic and reduce pollution level, contour structure is preferably embedded in transparent dielectric In, and dielectric is also above set on metal in this way.Therefore, term " above " not necessarily necessarily involves exposed table Face further relates to the upper surface of contour structure in the case where the upper surface of contour structure makes on elevated regions protrusion to substrate.

The Security element especially can be a part of the precursor material of valuable document, which is also not suitable for Circulation, and can also have more anti-counterfeiting characteristics.Valuable document, which is interpreted as referring to herein, must be able to prevent to replicate or forge File.The example of these valuable documents has banknote, bank-note paper, chip card or Antiforge card, such as bank card, credit card or identity Card.Security element can especially be integrated in anti-counterfeiting line, pull in item, tamper-proof strip, anti-counterfeiting code, patch or label.

It should be understood that the feature being mentioned above and the feature being discussed below not only can be by respective defined combined applications In specific embodiment, and without departing from the scope of the present invention, also by other combinations or can apply individually to have Body embodiment.

Detailed description of the invention

By way of example, present invention be described in more detail below with reference to accompanying drawings, and the attached drawing is disclosed for this hair Bright indispensable feature.In the accompanying drawings:

Fig. 1 is the schematic diagram with the banknote of anti-counterfeiting characteristic；

Fig. 2 is the sectional view of the anti-counterfeiting characteristic in first embodiment；

Fig. 3 is the sectional view of the anti-counterfeiting characteristic in second embodiment；

Fig. 4 is the sectional view of the anti-counterfeiting characteristic in 3rd embodiment；

Fig. 5 is the sectional view of the anti-counterfeiting characteristic in fourth embodiment；

Fig. 6 is the schematic diagram for showing the colour filter effect of Security element；

Fig. 7 is the schematic diagram set for showing the colour filter of Security element；

Fig. 8-10 shows the spectrogram of the reflectivity of the different embodiments of Security element；

Figure 11 and 12 shows the CIE color diagram of the different embodiments of Security element；

Figure 13 is the schematic diagram for showing the incident angle dependency of color effects；

Figure 14 shows a relevant CIE diagram；

Figure 15 and Figure 16 show other embodiments of Security element；With

Figure 17 shows the amplification views of the Security element of Fig. 1.

Specific embodiment

Fig. 1 shows the banknote 1 with Security element 2, which is applied to paper money as patch in the current situation On ticket paper.Security element 2 provide the pattern (being star 3 in the case) that is made of prospect element and with prospect obviously not Same background 4.Star 3 and background 4 are formed by means of the different Security element structure of geometric parameter, the Security element knot Structure and geometric parameter will be described hereinafter.

Fig. 2 shows the sectional views of the structure of Security element 2.One contour structure 6 is arranged on substrate 5.Fig. 2 shows cross Sectional view.Contour structure 6 includes multiple elevated regions 7, these elevated regions 7 are statistically divided with irregular each other and standard The distance of cloth is arranged.Fig. 2 shows two different distances, that is, the distance between center and left hand projection region d₁In and The distance between centre and right side elevated regions d₂.The elevated regions 7 of contour structure 6 are implemented in the form of a step.They, which have, covers Face 8, also, since they are the form of two steps in the embodiment shown in Figure 2, also there is another parallel step Face 9.Elevated regions 7 are located at 10 top of substrate.Clad can 8 is parallel both relative to substrate 10 with parallel surfaces 9.Step width is with b₁With b₂It indicates.They are identical in the diagram of Fig. 2, and are constant on all elevated regions 7.As described below, this Constancy be not it is indispensable, actually step width in a particular embodiment can be different.In elevated regions 7, Step height t₁And t₂It is always identical.Between different elevated regions 7, they can be different.This also will hereinafter be discussed It states.Elevated regions 7 and substrate 10 above on be metal.This can be by substrate 10 and elevated regions 10 by corresponding metal Change process forms to realize, as shown in Figure 2.In step height consistent in elevated regions 7 between 100 nanometers and 350 nanometers. In this region, metalization layer can be generated without difficulty, and is able to use photolithography method for example to construct metalization layer.

Fig. 3 shows a kind of version of the embodiment in Fig. 2.The difference for the second embodiment being shown here It is, firstly, the construction of contour structure 6 is different, secondly, contour structure is completely embedded into the dielectric.In second embodiment In, contour structure 6 is formed by the coining formation of paint layer 10 by applying metal coating on substrate 5.The coining paint Layer obtains the geometry of contour structure 6 in moulding process, coats metal coating 12, on it then to generate contour structure 6 metallization is above.Then, laminate 14 is set on contour structure 6, and coated with covering foil 15.Therefore, because metal layer 12 In the presence of contour structure 6 is upper above it to have dielectric constant v_M, and be embedded in refractive index n₁、n₂And n₃Dielectric material In material.

What the possessive construction mode that the first and second embodiments of Fig. 2 and Fig. 3 show Security element 2 may all have can Feature is selected, specifically, the adjacent area ratio that step width b is chosen so as to each step is roughly the same.It has been found that with This mode is able to achieve color effect as well as possible.

Fig. 4 and Fig. 5 shows the third and fourth embodiment with Fig. 3 according to fig. 2.But elevated regions 7 are formed with herein Five steps.The step height t of this five steps₁To t₅Also it is consistent.

Fig. 6 shows the effect of step-like elevated regions 7.Separate unit rank elevated regions 7 are shown in left side, are shown in center Two step elevated regions 7, on right side show five step elevated regions.Obviously, the step elevated regions 7 of the top of substrate 10 It shows similar with having the multi-ply construction of refractive index of alternately variation.As the ratio of step increases, with the reflection of angle, θ incidence The color saturation of radiation R is improved.Fig. 6 shows this point based on the optical path of each step.In 2 δ of path difference=n λ There is constructive interference in place, and wherein n is integer.Then, the wave of constructive interference at step is obtained according to formula λ=2t/nsin θ It is long.Therefore color effect can be set by step height.This is shown in FIG. 7, and substrate 10 is schematically illustrated in the figure Three of top have the two step elevated regions 7 of different step height t.They are chosen so as to generate blue B in reflection (left side), green G (center) and red R o (right side).

The hanging down in non-polarized light in the Security element 2 with two step profile structures 6 as shown in Figure 3 will be studied below The spectral reflectance in visible wavelength region under the conditions of straight incidence.Metal coating 12 in this is made of aluminium, and the electricity of surrounding The refractive index of medium is identical value (1.52).Fig. 9 shows reflectivity R with spectrum, wherein is different from the third embodiment It is that elevated regions 7 in the contour structure 6 studied in Fig. 8 are periodically arranged, there is fixed range d.Distance d is in fig. 8 Variation；Step height is consistent 150 nanometers of values.Curve (specifically 450 nanometer wave strong points) at blue light is shown Apparent maximum value.The position of the maximum value is unrelated with period d.The long wave light component of Zero-order diffractive is suppressed, to increase the period And enhance the color saturation in blue region.This shows that the periodic arrangement of elevated regions 7 is unfavorable.For this original Cause, in these embodiments, elevated regions are non-periodic arrangements, such as standard is statistically arranged.

Fig. 9 shows the zero level in the case where aluminum metal coating of the two step profile structures with consistent step height Spectral reflectance, wherein step height be in Fig. 9 variation.It is readily apparent that as described on the basis of Fig. 7, platform Rank height is readily apparent that define the color of reflected radiation R.The step height forms blue, green and red.

Figure 10 is shown in the case where having five step elevated regions 7 and identical contour structure 6 of other geometric parameters It is also above situation.It is obvious that step number is more, the reflection maximum of generation is more sharp.

It is special that Figure 11 and Figure 10 shows color of the contour structure measured in figures 9 and 10 in 1931 color space of CIE Property.The color characteristics be the susceptibility convolution of the launching curve and human eye by the reflectance spectrum that will calculate and D65 standard lamp simultaneously It is converted into the acquisition of color coordinates x, y, z.These charts are bright, in both cases, have step-like elevated regions 7 Contour structure 6 present RGB color.It is also clear that the five step raised profiles analyzed in Figure 12 provide especially saturation Green tone.

Fig. 3 shows the influence of the dependence of angle of reflected radiation R.Which depict two incidence angles, 0 ° and 30 °.Figure 13 based on the contour structure with four step elevated regions.Step height is also 150 nanometers.When 30 ° of ranges are tilted, blue Maximum value in region is hardly displaced.Figure 14 shows in 1931 chromatic graph of CIE 150 nanometers, 180 nanometers and 210 nanometers The case where step height.In inclination, blue, green and red three kinds of color keeps its tones.Reflection colour to angle very High tolerance is obvious.This is particularly advantageous for generating pattern, especially in the environmental condition for generally including diffused light Under when being observed.The characteristic that reflection colour height depends on angle will lead to unnecessary color mixing, thus be obviously reduced Color effect.

The color obtained in reflection is substantially characterized by the refractive index of step height t and surrounding dielectric.As long as can keep away Exempt from periodic arrangement, the influence of step width b and each distance is exactly secondary property.

Figure 15 shows one embodiment of Security element 2, which has separate unit rank convex in contour structure 6 Region 7 is played, which aperiodically arranges, specifically standard is statistically distributed.Figure 16 shows The same case of two step elevated regions is gone out, wherein the step width in elevated regions is variation.

Figure 17 shows the plan views of the Security element 2 in Fig. 1, and the Security element 2 has wheel as shown in figure 15 herein Wide structure.Elevated regions 7 are aperiodically arranged on two spaces direction, wherein having selected for star 3 and background 4 different Step height.This can not see in the plan view of Figure 17 certainly.Between the region and background 4 of star 3 shown in the figure Separator bar is only used for showing zone boundary, because can not find out step height in the plan view.

As soon as being enough to generate color effect when elevated regions on direction in space arrange by aperiodicity；Shown in Figure 17 The aperiodicity on two spaces direction improve effect.

The contour structure can be generated by embossment structure well known in the prior art, such as be mentioned in preface part special Described in benefit bulletin.Elevated regions with multiple steps are usually to pass through multi-step etch process to obtain, alternatively, for wheel Wide structure is by the way that the coining in material to be imprinted (such as can ultraviolet curing coining paint) generates the case where, is by more Step molding obtains.

The advantages of anti-counterfeiting characteristic is to can be achieved with color by single metal layer.It no longer needs in multilayer system In the case of needed for the complex multilayer with different refractivity.In addition, the contour structure can be realized with extraordinary The high resolution design of resolution ratio, because can accurately set spatial resolution by moulding process.Therefore, each region Optical effect can also especially be realized in a manner of perfect alignment relative to each other.In this way, in single anti-counterfeiting characteristic In can combine Space, movement effects and multicolour pattern.

Reference signs list

1 banknote

2 Security elements

3 stars

4 backgrounds

5 substrates

6 contour structures

7 elevated regions

8 clad cans

9 step surfaces

10 substrates

11 coining paints

12 metal coatings

14 laminates

15 cover foil

Claims (7)

1. a kind of Security element with reflection colour filter characteristic, the Security element is valuable for manufacturing banknote (1), check etc. File, this valuable document have the contour structure (6) for having elevated regions (7) on substrate (10) and metal,

It is characterized by:

Elevated regions (7) have the clad can (8) parallel relative to substrate (10), and when observing in cross-section, each protrusion Region (7) has step height (t) at least formed with single step, the step, and relative to the position on substrate (10) And/or range is aperiodically distributed, wherein step height (t) is at least consistent in local level, and step height (t) between 100 nanometers and 350 nanometers.

2. Security element as described in claim 1, which is characterized in that each elevated regions (7) have two to two ten steps.

3. Security element as claimed in claim 1 or 2, which is characterized in that different regions (3,4) are formed with, in these areas In domain, elevated regions (7) are all consistent in terms of numbers of steps and step height (t) in each case, wherein region (3, 4) different in terms of numbers of steps and/or step height (t) and/or step width (b).

4. Security element as described in any one of the preceding claims, which is characterized in that the contour structure (6) is by transparent material Expect that (11) are formed, and is covered with metal layer (12).

5. Security element as described in any one of the preceding claims, which is characterized in that the contour structure (6) is embedded in In bright dielectric (14).

6. a kind of valuable document has the Security element (2) as described in any one of claims 1 to 5.

7. the manufacturing method of Security element (S) of the one kind for manufacturing the valuable documents such as banknote (1), check, wherein generate There is the contour structure (6) of elevated regions (7) on above the substrate (10) and metal,

It is characterized by:

Elevated regions (7) have the clad can (8) parallel relative to substrate (10), and when observing in cross-section, each protrusion Region (7) has step height (t) at least formed with single step, the step, and relative to the position on substrate (10) And/or range is aperiodically distributed, wherein step height (t) is at least consistent in local level, and step height (t) between 100 nanometers and 350 nanometers.