Abstract: The invention relates to a security feature having a luminescent component and a component camouflaging the luminescent component. The invention starts out from a security feature having a luminescent component having at least one luminophore consisting of at least one doped host lattice, and a component camouflaging the luminescent component, wherein the camouflaging component has chemical elements that have similar structure-chemical properties to the chemical elements of the luminescent component, wherein the chemical elements of the camouflaging component and the chemical elements of the luminescent component are formed by different chemical elements.

Abstract: A method for producing solid particles having a silica coating, by: dispersing the solid particles to be coated in an aqueous medium to produce a solid particle dispersion, adjusting the pH of the solid particle dispersion by a buffer system to produce a buffered solid particle dispersion, and adding an alkaline silicate solution to the buffered solid particle dispersion to form the silica coating on the solid particles during a coating period. The amounts of buffer system and alkaline silicate solution are selected such that the pH of the buffered solid particle dispersion before the addition of the alkaline silicate solution is at least 7.0 and after completion of the addition of the alkaline silicate solution is at most 11.0.

Abstract: The invention relates to a security feature having a luminescent component and a component camouflaging the luminescent component. The invention starts out from 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, in which the camouflaging component has at least two substances, the first substance of the camouflaging component having an X-ray diffractogram which hides the X-ray diffractogram of the luminescent component, and the second substance of the camouflaging component having at least one cationic element of the luminescent component and at least one cationic element of the first substance of the camouflaging component, with the luminescent component and the first substance of the camouflaging component being formed of different cationic elements.

Abstract: The invention relates to a security feature having a luminescent substance with the general formula AXO3:Z (I) or B0.5XO3:Z (II) or A1-2yByXO3:Z (III), where A is an alkali metal, B is an alkaline earth metal, X stands for Nb or Ta, Z is the luminescence activator, and y lies between 0 and 0.5. The invention also relates to a security element, a security paper and a value document which is equipped with the security feature according to the invention, and to the use of the luminescent substance with the general formula (I), (II) or (III) as a feature substance for authentication. The luminescent substance is obtained by annealing solid starting materials.

Abstract: The invention relates to a security feature with a luminescent pigment which has a host lattice doped with a luminophore and which is optically excitable to emit luminescent light. The luminescent light of the luminescent pigment has a luminescence spectrum with a first luminescence peak and a second luminescence peak whose peak intensities respectively depend on an amount fraction x of the luminophore in the luminescent pigment. In the luminescent pigment according to the invention, the host lattice and the luminophore and the amount fraction x of the luminophore are chosen such that even a slight increase or reduction of the amount fraction x of the luminophore causes a strong relative change of the peak intensities IA and IB. This increases the forgery-proofness of the luminescent pigment according to the invention.

Abstract: A method for producing solid particles having a silica coating, by: dispersing the solid particles to be coated in an aqueous medium to produce a solid particle dispersion, adjusting the pH of the solid particle dispersion by a buffer system to produce a buffered solid particle dispersion, and adding an alkaline silicate solution to the buffered solid particle dispersion to form the silica coating on the solid particles during a coating period. The amounts of buffer system and alkaline silicate solution are selected such that the pH of the buffered solid particle dispersion before the addition of the alkaline silicate solution is at least 7.0 and after completion of the addition of the alkaline silicate solution is at most 11.0.

Abstract: The invention relates to a security feature for securing documents of value having a plurality of microcapsules, which respectively have a wall and in which is respectively contained a liquid medium in which are distributed several magnetic particles which are movable in the liquid medium and whose arrangement within the microcapsule is changeable by the action of a magnetic field, whereby the magnetic particles are configured to arrange themselves within the microcapsule such that they form a light-diffractive structure.