Patent · US Expired

Substrates secure against unauthorized copying and processes for their preparation

US5425978A · kind A · utility

53Cited by

1References

7Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Horst Berneth · Leverkusen, DE
Uwe Claussen · Leverkusen, DE

Key dates

Filing date	Oct 19, 1993
Grant date	Jun 20, 1995
Priority date	—
Expiry date	Oct 19, 2013

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/24934
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

Novel substrates bearing visible information applied thereto give indiscernible, for example illegible, photocopies when the information applied using colorant combinations of at least one emitting and at least one reflecting colorant whose shades upon viewing without fluorescence being perceived are similar or identical.

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