The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1997
Filed:
Jan. 12, 1988
Applicant:
Inventors:
Assignee:
Sicipa Holding S.A., , CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09D / ;
U.S. Cl.
CPC ...
106 3137 ; 523161 ;
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.