Security feature having several components

Abstract

A security feature has a luminescent component and a component camouflaging the luminescent component. A security feature has a luminescent component with at least one luminophore consisting of a doped host lattice, and a component camouflaging the luminescent component, wherein for camouflaging the luminescent component, relevant properties required for identifying the luminescent component are camouflaged by the camouflaging component by the relevant properties of the luminescent component. The relevant properties being camouflaged by the camouflaging component in at least two of the relevant properties by the camouflaging component having relevant properties that correspond to the respective relevant properties of the luminescent component, thereby impeding or preventing a recognition of the luminescent component.

Claims

1. A security feature having a luminescent component having at least one luminophore consisting of a doped host lattice, and a component camouflaging the luminescent component, wherein an identification of the luminescent component is impeded or prevented by properties of the camouflaging component and respective like-kind properties of the luminescent component being characterized by the following relations: a) the camouflaging component has a X-ray diffractogram that at least partly overlaps with, but is not identical to, the X-ray diffractogram of the luminescent component, in order to camouflage the structure of the luminescent component, b) the camouflaging component contains at least one cationic element that is also contained in a host lattice of the luminescent component, but not all cationic elements contained in this host lattice, in order to camouflage the stoichiometry of the luminescent component, c) the camouflaging component contains at least one cationic element that is not contained in a host lattice of the luminescent component, in order to camouflage the elemental constitution of this host lattice of the luminescent component, d) the camouflaging component contains at least one dopant that is not contained as a dopant in the luminescent component, in order to camouflage the dopant or dopants of the luminescent component, e) the camouflaging component contains at least one luminophore that has a lower decay time than the luminophore contained in the luminescent component, in order to camouflage the spectral properties of the luminescent component, said security feature being further wherein the properties of the camouflaging component and of the luminescent component satisfy relation a) and at least one of the relations stated in b) to e).

2. The security feature according to claim 1, wherein the camouflaging component and the luminescent component satisfy the relations a) and b).

3. The security feature according to claim 1, wherein the camouflaging component and the luminescent component satisfy the relations a), b), c) and d).

4. The security feature according to claim 1, wherein the camouflaging component and the luminescent component satisfy the relations a) and e).

5. The security feature according to claim 1, wherein the camouflaging component and the luminescent component satisfy the relations a), b), c), d) and e).

6. The security feature according to claim 1, wherein the X-ray diffractogram of the luminescent component and the X-ray diffractogram of the camouflaging component have a partial overlap in significant peaks, with at least one relevant peak position overlapping.

7. The security feature according to claim 6, wherein the overlapping peaks have at least 30% of the height of a main peak.

8. The security feature according to claim 6, wherein the overlapping peaks are a main peak of luminescent component and camouflaging component.

9. The security feature according to claim 1, wherein the cationic elements are selected from the main group elements Li, Be, B, Na, Mg, Al, Si, P, S, K, Ca, Ga, Ge, As, Se, Rb, Sr, In, Sn, Sb, Te, Cs, Ba, Tl, Pb, Bi or the elements of the transition metals or the rare earth elements.

10. The security feature according to claim 1, wherein the dopant of the luminescent component is a rare earth element, and the camouflaging component contains at least one dopant consisting of the elements of the rare earths Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb.

11. The security feature according to claim 1, wherein the dopant of the luminescent component is a transition metal of the fourth period of the periodic system, and the camouflaging component contains at least one other dopant consisting of the elements of the fourth period of the periodic system.

12. The security feature according to claim 1, wherein the luminophore of the camouflaging component is an organic luminophore.

13. The security feature according to claim 1, wherein the luminophore has a decay time of less than 10 s.

14. The security feature according to claim 1, wherein the camouflaging component has, in addition to the at least partly overlapping X-ray diffractogram, at least one further structural feature that at least partly match corresponding structural features of the luminescent component, in order to camouflage the structure of the luminescent component, wherein the at least one further structural feature comprises at least a production component or a coding component.

15. A value document having a security feature according to claim 1, wherein the value document consists of paper and/or plastic.

16. The value document according to claim 14, wherein the security feature is incorporated into the volume of the value document and/or applied to the value document.

17. The value document according to claim 14, wherein the security feature is applied to the value document as an invisible, at least partial coating.

18. A security feature having a luminescent component having at least one luminophore consisting of a doped host lattice, and a component camouflaging the luminescent component, wherein an identification of the luminescent component is impeded or prevented by properties of the camouflaging component and respective like-kind properties of the luminescent component being characterized by the following relations: a) the camouflaging component contains at least one cationic element that is also contained in a host lattice of the luminescent component, but not all cationic elements contained in this host lattice, in order to camouflage the stoichiometry of the luminescent component, b) the camouflaging component contains at least two cationic elements that are not contained in a host lattice of the luminescent component in a quantity of at least 30% of the molar quantity of a cationic matrix element, in order to camouflage the elemental constitution of this host lattice of the luminescent component, c) the camouflaging component contains at least two dopants that are not contained as a dopant in the luminescent component, in order to camouflage the dopant or dopants of the luminescent component, d) the camouflaging component contains at least one luminophore that has a lower decay time than the luminophore contained in the luminescent component, in order to camouflage the spectral properties of the luminescent component, said security feature being further wherein the properties of the camouflaging component and of the luminescent component satisfy all four of the relations stated in a) to d).

Description

Example 1

(1) As a luminescent component (M) there is used a luminescent substance CaNb.sub.2O.sub.6:Nd consisting of a host lattice (matrix) of calcium niobate which is doped with neodymium, which was produced by annealing a mixture of 2.675 g CaCO.sub.3, 7.234 g Nb.sub.2O.sub.5 and 0.092 g Nd.sub.2O.sub.3 for 10 h at 1150 C. Upon excitation at 532 nm the luminescent component emits at 1061 nm. The main peak in the diffractogram of the luminescent component lies here at 29.2.

(2) For structural camouflage (R) there can be used monoclinic Zr(MoO.sub.4).sub.2 whose main peak lies at 29.1. Simultaneously, through Zr(MoO.sub.4).sub.2 the additional cationic elements Zr and Mo are incorporated for elemental camouflage (E). For camouflaging the stoichiometry (S) of the luminescent component, Nb.sub.2O.sub.5 can be added. Nb.sub.2O.sub.5 can likewise be used for production compensation (P). As a coding component (K) there is employed CaTa.sub.2O.sub.6:Sm.sub.0.03 (emission at 610 nm). For camouflaging the dopants (D) there are employed small quantities of Er.sub.2O.sub.3 and Yb.sub.2O.sub.3.

(3) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(4) 40% CaNb.sub.2O.sub.6:Nd (M)

(5) 30% Zr(MoO.sub.4).sub.2 (R, E)

(6) 26% Nb.sub.2O.sub.5 (S, F)

(7) 2.5% CaTa.sub.2O.sub.6:Sm (K)

(8) 1% Er.sub.2O.sub.3 (D)

(9) 0.5% Yb.sub.2O.sub.3 (D)

Example 2

(10) The luminescent component (M) is identical to the luminophore described in Example 1. The structure is not camouflaged. A camouflage of the stoichiometry (S) is obtained by adding Ca.sub.3(PO.sub.4).sub.2. The element P of the substance Ca.sub.3(PO.sub.4).sub.2 moreover effectuates an elemental camouflage (E). Additional cationic elements (E) Sr and Al are incorporated by adding SrAl.sub.2O.sub.4. As a production compensation (P) there is employed Sr.sub.3(PO.sub.4).sub.2. The elements Sr and P of the substance employed for the production compensation moreover effectuate an elemental camouflage (E). For camouflaging the dopants (D) there are used small quantities of Yb.sub.2O.sub.3 and Tm.sub.2O.sub.3. The coding component (K) is identical to that in Example 1.

(11) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(12) 35% CaNb.sub.2O.sub.6:Nd (M)

(13) 20% Ca.sub.3(PO.sub.4).sub.2 (S, E)

(14) 20% SrAl.sub.2O.sub.4 (E)

(15) 20% Sr.sub.3(PO.sub.4).sub.2 (P, E)

(16) 3% CaTa.sub.2O.sub.6:Sm (K)

(17) 1% Yb.sub.2O.sub.3 (D)

(18) 1% Tm.sub.2O.sub.3 (D)

Example 3

(19) On the basis of the substances from Example 1 the luminescence emission is additionally camouflaged by two organic luminophores (L). These involve a mixture of a tetranuclear neodymium complex with 2-thenoyltrifluoroacetone (HTTA) as a ligand, which fluoresces in the region of 1050-1100 nm, and the commercially available polymethine IR-1061 (Sigma Aldrich), which fluoresces in the region of 1020-1180 nm.

(20) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(21) 30% CaNb.sub.2O.sub.6:Nd (M)

(22) 30% Zr(MoO.sub.4).sub.2 (R, E)

(23) 26% Nb.sub.2O.sub.5 (S, P)

(24) 5% Nd.sub.4(TTA).sub.10O.sub.12H.sub.22 (L)

(25) 5% IR-1061 (L)

(26) 2.5% CaTa.sub.2O.sub.6:Sm (K)

(27) 1% Er.sub.2O.sub.3 (D)

(28) 0.5% Yb.sub.2O.sub.3 (D)

Example 4

(29) As a luminescent component (M) there is used a Y.sub.1.98Nd.sub.0.02SiO.sub.5 which was produced by mixing 2.66 g urea, 0.53 g SiO.sub.2, 6.72 g Y(NO.sub.3).sub.3.6H.sub.2O, 0.08 g Nd(NO.sub.3).sub.3.5H.sub.2O and 3 mL H.sub.2O, evaporating the liquid at 500 C., and annealing the obtained material at 1500 C. for 10 h. Upon excitation at 532 nm the luminescent component emits at 1075 nm.

(30) A significant peak (>70% of main peak) in the X-ray diffractogram lies at 22.8. For camouflaging the X-ray diffractogram (R) there can be employed NaTaO.sub.3, whose main peak lies at 22.8. The elements Na and Ta moreover effectuate an elemental camouflage (E). A camouflage of the stoichiometry (S) and incorporation of additional cationic elements (E) is obtained by adding YAlO.sub.3. YAlO.sub.3 can likewise be employed as a production compensation (P). For camouflaging the dopants (D) there are used small quantities of Yb.sub.2O.sub.3 and Ce.sub.2O.sub.3. As a coding component (K) there is employed LaOBr:Tb (emission at 543 nm).

(31) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(32) 35% Y.sub.1.98Nd.sub.0.02SiO.sub.5 (M)

(33) 30% NaTaO.sub.3 (R, E)

(34) 31% YAlO.sub.3 (S, E, P)

(35) 2% LaOBr:Tb (K)

(36) 1% Yb.sub.2O.sub.3 (D)

(37) 1% Ce.sub.2O.sub.3 (D)

Example 5

(38) The luminescent component (M) is identical to the luminophore described in Example 4. For camouflaging the stoichiometry (S) and incorporating additional cationic elements (E) there is used NaAlSiO.sub.4. As a production compensation (P) and for incorporating additional cationic elements (E) there is used BaSO.sub.4. For camouflaging the dopants (D) there are used small quantities of Tm.sub.2O.sub.3 and Sm.sub.2O.sub.3. The coding component (K) is identical with that from Example 4.

(39) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(40) 40% Y.sub.1.98Nd.sub.0.02SiO.sub.5 (M)

(41) 30% NaAlSiO.sub.4 (S, E)

(42) 26% BaSO.sub.4 (P, E)

(43) 2% LaOBr:Tb (K)

(44) 1% Tm.sub.2O.sub.3 (D)

(45) 1% Sm.sub.2O.sub.3 (D)

Example 6

(46) On the basis of the substances from Example 4 the luminescence emission is additionally camouflaged by an organic luminophore (L). The latter is IR-1048 (Sigma Aldrich), which fluoresces in the region of 1050-1150 nm.

(47) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(48) 30% Y.sub.1.98Nd.sub.0.02SiO.sub.5 (M)

(49) 30% NaTaO.sub.3 (R, E)

(50) 30% YAlO.sub.3 (S, E, P)

(51) 5% IR-1048 (L)

(52) 3% LaOBr:Tb (K)

(53) 1% Yb.sub.2O.sub.3 (D)

(54) 1% Ce.sub.2O.sub.3 (D)

Example 7

(55) As a luminescent component (M) there is used a KTiO(PO.sub.4):Er which was produced by annealing a mixture of 18.78 g KH.sub.2PO.sub.4, 10.90 g TiO.sub.2 and 0.61 g Er.sub.2O.sub.3 at 800 C. for 12 h. Upon excitation at 520 nm the luminescent component emits at 1540 nm. The main peak in the diffractogram of the luminescent component lies at 32.3, with a closely adjacent significant peak (>70% of the main peak) at 32.6. For camouflaging the X-ray diffractogram (R) there can be used LaMnO.sub.3, which possesses two significant peaks (90-100% of the main peak) at 32.3 and 32.6 in the diffractogram. The elements La and Mn moreover effectuate an elemental camouflage (E). For camouflaging the stoichiometry (S) there can be added TiO.sub.2, which can simultaneously be employed as a production compensation (P). For camouflaging the dopants (D) there are used small quantities of Nd.sub.2O.sub.3, Ce.sub.2O.sub.3 and Ho.sub.2O.sub.3. The coding component (K) is Y.sub.2SiO.sub.5:Ce, which emits at 420 nm.

(56) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(57) 30% KTiO(PO.sub.4):Er (M)

(58) 30% LaMnO.sub.3 (R, E)

(59) 35% TiO.sub.2 (S, P)

(60) 2% Y.sub.2SiO.sub.5:Ce (K)

(61) 1% Ce.sub.2O.sub.3 (D)

(62) 1% Nd.sub.2O.sub.3 (D)

(63) 1% Ho.sub.2O.sub.3 (D)

Example 8

(64) The luminescent component (M) is identical to the luminophore described in Example 7. For camouflaging the stoichiometry (S) and incorporating additional cationic elements (E) there is employed CaTiO.sub.3. Additional cationic elements (E) are incorporated by adding ZrSiO.sub.4, which can simultaneously serve as a production compensation (P). For camouflaging the dopants (D) there are used small quantities of Nd.sub.2O.sub.3, Ce.sub.2O.sub.3 and Ho.sub.2O.sub.3. The coding component (K) is identical to that in Example 7.

(65) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(66) 30% KTiO(PO.sub.4):Er (M)

(67) 30% CaTiO.sub.3 (S, E)

(68) 35% ZrSiO.sub.4 (E, P)

(69) 2% Y.sub.2SiO.sub.5:Ce (K)

(70) 1% Ce.sub.2O.sub.3 (D)

(71) 1% Nd.sub.2O.sub.3 (D)

(72) 1% Ho.sub.2O.sub.3 (D)

Example 9

(73) On the basis of the substances from Example 8 the luminescence emission is additionally camouflaged by an organic luminophore (L). The latter is the acyclic erbium complex acyc-H, as is described in the literature source L. Slooff, A. Polman, M. Oude Wolbers, F. van Veggel, D. Reinhoudt, J. Hofstraat; J. Appl. Phys. 83 (1) 1998, p. 497-503, which fluoresces in the region of 1480-1600 nm.

(74) A security feature comprising luminescent component and camouflaging component with production compensation and coding component then has for example the composition:

(75) 28% KTiO(PO.sub.4):Er (M)

(76) 28% CaTiO.sub.3 (S, E)

(77) 29% ZrSiO.sub.4 (E, P)

(78) 10% acyc-H (L)

(79) 2% Y.sub.2SiO.sub.5:Ce (K)

(80) 1% Ce.sub.2O.sub.3 (D)

(81) 1% Nd.sub.2O.sub.3 (D)

(82) 1% Ho.sub.2O.sub.3 (D)