Optically variable security element comprising optically variable colour layer

摘要

The invention relates to an optically variable security element (14) for safeguarding valuable articles, comprising an optically variable colour layer (34). The invention provides for the optically variable colour layer (34) to contain a multiplicity of microcapsules (36) each having a capsule enclosure (38), a carrier liquid (40) enclosed in the capsule enclosure (38) and at least one optically variable and magnetically alignable pigment (42), which in the microcapsule (36) is substantially freely rotatable and reversibly alignable by an external magnetic field (24) and which is embodied in multilayered fashion with at least one magnetic layer (46) and with at least one non-magnetic layer (48) (e.g. silicon dioxide or graphene layers as carbon sheathing (84), as protection against oxidation).