Patent · US Expired

Security document with reversibly photochromic printing inks

US5807625A · kind A · utility

49Cited by

7References

26Claims

0Family size

Assignee

SICPA HOLDING SA · CH

Inventors

Albert Amon · Lausanne, CH
Haim Bretler · Lausanne, CH
Anton Bleikolm · Ecublens, CH

Key dates

Filing date	Jun 17, 1996
Grant date	Sep 15, 1998
Priority date	—
Expiry date	Jun 17, 2016

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/254
WIPO fieldOther consumer goods
WIPO sectorOther fields

Abstract

Photochromic printing inks are disclosed which are in particular used for the printing of security documents. Prints are normally nearly colorless and become colored when energy irradiated, such as by ultraviolet light. This photocoloration is reversible. The printing inks contain photochromic compounds which are protected against other ink components. Methods are described to prepare the inks, to print security documents, and to detect counterfeiting.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.