Coatings for use with business forms, security documents, or safety paper
US5250492A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1991 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Mar 7, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M3/142
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Carbonless coating compositions which can be printed onto one or more sheets of a business form or mailer to provide a visible image which is sharper and darker than previous coatings are provided. The compositions also find use on security documents and safety papers to provide a covert image on the document beneath information which may be subject to attempted alteration, such as the amount written on a check. The covert image becomes visible upon the application of pressure or solvent in the area coated to provide evidence of the attempted alteration. The self-contained composition includes an admixture of a color former, a color developer, and a plurality of pressure-rupturable microcapsules containing a solvent. Another solvent-sensitive composition includes an admixture of a color former and a color developer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.