OPTICALLY VARIABLE SECURITY THREADS AND STRIPES

摘要

An optically variable security thread or stripe (T) is provided which could be incorporated into or onto security documents. The security thread or stripe comprises: a) an optically variable layer (1), b) a color constant layer (2) having a color matching the color impression of the optically variable layer at a viewing angle, c) a holographic metallic layer (3) and d) a substrate (4), wherein the optically variable layer, the color constant layer and the holographic metallic layer are at least partially jointly visible from the side of the security thread or stripe comprising the optically variable layer and/or the color constant layer.

主权项

1. A security thread or stripe comprising:
a) an optically variable layer imparting a different color impression at different viewing angles and being made of an optically variable composition comprising from about 2 to about 40 wt-% of optically variable pigments, said optically variable layer comprising one or more gaps in the form of indicia or consist of indicia made of the optically variable composition, the weight percents being based on the total weight of the optically variable composition; b) a color constant layer having a color matching the color impression of the optically variable layer at a viewing angle, and being made of color constant composition comprising from about 1 to about 20 wt-% of one or more dyes and/or from about 0.1 to about 45 wt-% of inorganic pigments, organic pigments or mixtures thereof, said color constant layer either comprising one or more gaps in the form of indicia or consist of indicia made of the color constant composition, the weight percents being based on the total weight of the color constant composition; c) a holographic metaffic layer; and d) a substrate wherein i) the holographic metaffic layer faces the substrate, ii) the color constant layer and the optically variable layer are present on top of the holographic metaffic layer and iii) the color constant layer and/or the optically variable layer faces the environment, and wherein the optically variable layer, the color constant layer and the holographic metallic layer are at least partially jointly visible from the side of the security thread or stripe comprising the optically variable layer and/or the color constant layer.