Security features, their use and processes for making them

A digitally-printed reflective security feature.

A security feature, comprising:

• (a) a substrate having a surface, the surface comprising an image;
• and
• (b) a reflective layer comprising metallic particles disposed on at least a portion of the surface and at least partially overlapping the image.

A process for forming a reflective security feature, the process comprising the steps of:

• (a) providing an ink comprising metallic particles;
• and
• (b) direct write printing the ink to form the reflective security feature.

The process of claim 1101, wherein the image is selected from the group consisting of a hologram, a black and white image, a color image, a watermark, a UV fluorescent image, text and a serial number.

A direct write printing process for printing a security feature utilizing a direct write printer having a direct write head, the direct write head capable of generating and depositing droplets of an ink on a substrate, the ink comprising metallic particles, the process comprising the steps of operating the direct write head at greater than 5000 s−1 such that each drop of ink generated comprises about 5 picoliters to about 100 picoliters of the ink, and wherein the substrate is moving at a rate of greater than 1 m/s.

A process for forming reflective security features, the process comprising the steps of:

• (a) providing an ink comprising metallic particles;
• and
• (b) printing the ink onto a substrate to form the reflective security features at a rate greater than 1 m/s, based on the rate of the substrate.

A security feature comprising metallic particles and exhibiting a conductivity authentication feature.

A UV curable security feature comprising metallic particles and free of a UV curable organic composition.

A substantially non-conductive UV curable security feature comprising conductive portions or components, wherein the security feature is free of a UV curable composition.

A security feature, comprising:

• (a) a first layer comprising first metallic particles, the first metallic particles comprising a first metal oxide;
• and
• (b) a second layer disposed at least in part on the first layer, the second layer comprising second metallic particles comprising a second metal oxide.