Birefringent marking

US7495740B2 · kind B2 · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Robert Hammond-Smith · Fordingbridge, GB
• John Patrick · Carthage, US
• Rodney Riddle · Holzminden, DE
• Matthias Kuntz · Seeheim-Jugenheim, DE
• Michael Ukelis · Riedstadt, DE
• Peter Schmitt · Erlangen, DE
• Siegfried Schmitzer · Schweinfurt, DE

Key dates

• Filing date: Aug 8, 2003
• Grant date: Feb 24, 2009
• Expiry date: May 14, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G07D7/0032
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

The invention relates to a method of preparing a birefringent marking by printing a polymerisable liquid crystal material onto at least one side of a substrate and polymerising the liquid crystal material, to a birefringent marking obtained by this method, and to the use of the birefringent marking for decorative, security, authentification and identification applications.