Security devices

US10166811B1 · kind B1 · utility

Inventors

• John S. Lettow · Washington, US
• Dan Scheffer · Frederick, US

Key dates

• Filing date: Mar 22, 2018
• Grant date: Jan 1, 2019
• Expiry date: Mar 22, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B42D2033/20
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A combination comprising a document having an image applied thereto and a security device affixed to a surface of the document. The security device comprising a first layer applied on the image. The first layer comprising a first and a second portion in communication with a first and second image area of the image, respectively. The first layer comprising a coating composition comprising fully exfoliated single sheets of graphene. The first portion comprises: a first detectable property having a first value correlated with the fully exfoliated single sheets of graphene; a first X-ray diffraction pattern; and a first electrical conductivity. The second portion comprises a second detectable property comprising: a second value correlated with the fully exfoliated single sheets of graphene; a second X-ray diffraction pattern; and a second electrical conductivity. The first and second detectable properties are not equal and together create a distinctive signature.