Security element and method for producing same

A security arrangement for security papers, valuable articles and the like, having:

• a security element for securing valuable articles, having a first optically active layer that is present in at least some areas and comprises cholesteric liquid crystal material, and a second optically active layer that is present in at least some areas, the first and the second layer being stacked in an overlap area, characterized in that the first optically active layer selectively reflects light in a first wavelength range having a first direction of circular polarization, the second optically active layer, either itself or, in the overlap area, in coaction with the first optically active layer, selectively reflects light in a second wavelength range having a second direction of circular polarization, that the second optically active layer forms a phase-shifting layer, that the second optically active layer forms a λ/2 layer for light from the first wavelength range and that the second optically active layer is present in the form of characters and/or patterns;
• or,
• a security element manufacturable according to a method in which a first and a second optically active layer are applied to a substrate foil such that they are stacked in an overlap area, a cholesteric liquid crystal material being applied to form the first optically active layer, and wherein the second optically active layer is provided in the form of a phase-shifting layer, namely a λ/2 layer for light from the first wavelength range, and is provided in the form of characters and/or patterns;
• and
• a separate display element that, in coaction with the security element or the security element so manufacturable, makes a color shift effect and/or a polarization effect and/or a brightness effect perceptible for the viewer.

A valuable article, such as a branded article, value document or the like, having:

• a security element for securing valuable articles, having a first optically active layer that is present in at least some areas and comprises cholesteric liquid crystal material, and a second optically active layer that is present in at least some areas, the first and the second layer being stacked in an overlap area, characterized in that the first optically active layer selectively reflects light in a first wavelength range having a first direction of circular polarization, the second optically active layer, either itself or, in the overlap area, in coaction with the first optically active layer, selectively reflects light in a second wavelength range having a second direction of circular polarization, that the second optically active layer forms a phase-shifting layer, that the second optically active layer forms a λ/2 layer for light from the first wavelength range and that the second optically active layer is present in the form of characters and/or patterns;
• or,
• a security element manufacturable according to a method in which a first and a second optically active layer are applied to a substrate foil such that they are stacked in an overlap area, a cholesteric liquid crystal material being applied to form the first optically active layer, and wherein the second optically active layer is provided in the form of a phase-shifting layer, namely a λ/2 layer for light from the first wavelength range, and is provided in the form of characters and/or patterns.

A method for checking the authenticity of:

• a security element for securing valuable articles, having a first optically active layer that is present in at least some areas and comprises cholesteric liquid crystal material, and a second optically active layer that is present in at least some areas, the first and the second layer being stacked in an overlap area, characterized in that the first optically active layer selectively reflects light in a first wavelength range having a first direction of circular polarization, the second optically active layer, either itself or, in the overlap area, in coaction with the first optically active layer, selectively reflects light in a second wavelength range having a second direction of circular polarization, that the second optically active layer forms a phase-shifting layer, that the second optically active layer forms a λ/2 layer for light from the first wavelength range and that the second optically active layer is present in the form of characters and/or patterns;
• a security element manufacturable according a method in which a first and a second optically active layer are applied to a substrate foil such that they are stacked in an overlap area, a cholesteric liquid crystal material being applied to form the first optically active layer, and wherein the second optically active layer is provided in the form of a phase-shifting layer, namely a λ/2 layer for light from the first wavelength range, and is provided in the form of characters and/or patterns;
• a security arrangement for security papers, valuable articles and the like, having said security element or said security element so manufacturable;
• and a separate display element that, in coaction with the security element or the security element so manufacturable, makes a color shift effect and/or a polarization effect and/or a brightness effect perceptible for the viewer;
• or
• a valuable article, such as a branded article, value document or the like, having said security element or the security element so manufacturable;
• characterized;
• in that the security element, the security element so manufacturable, the security arrangement, or the valuable article is checked whether a predefined color shift effect is present and/or whether a predefined polarization effect and/or a predefined brightness effect is present, and the authenticity of the checked element is assessed on the basis of the check result.