Methods for producing optical effect layers comprising magnetic or magnetizable pigment particles and exhibiting one or more indicia
US12311406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2022 |
| Grant date | May 27, 2025 |
| Priority date | — |
| Expiry date | Jun 24, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/54
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention relates to the field of the protection of security documents such as for example banknotes and identity documents against counterfeit and illegal reproduction. In particular, the present invention provides methods for producing optical effect layers exhibiting one or more indicia on a substrate, said method comprising a step of exposing a coating layer comprising non-spherical magnetic or magnetizable pigment particles to a magnetic field of a magnetic-field generating device so as to orient at least a part of the magnetic or magnetizable pigment particles; a step of applying a top coating composition on top of the coating layer and in the form of one or more indicia, and a step of at least partially curing the coating layer and the one or more indicia with a curing unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.