Magnetic or magnetisable pigment particles and optical effect layers
US10279618B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2014 |
| Grant date | May 7, 2019 |
| Priority date | — |
| Expiry date | Sep 3, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09C2200/24
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The invention relates to the field of non-spherical magnetic or magnetisable pigment particles and coating compositions comprising those pigment particles for producing optical effect layers (OEL) wherein the magnetic or magnetisable pigment particles are magnetically oriented. In particular, the present invention provides uses of said optical effect layers (OEL) layers as anti-counterfeit means on security documents or security articles. In particular, it relates to the field of non-spherical magnetic or magnetisable pigment particles comprising a magnetic metal selected from the group consisting of cobalt, iron, gadolinium and nickel; a magnetic alloy of iron, manganese, cobalt, nickel, or a mixture of two or more thereof; a magnetic oxide of chromium, manganese, cobalt, iron, nickel or a mixture of two or more thereof; or a mixture of two or more thereof, and having a d50 value higher than 6 μm and lower than 13 μm, their uses in coating compositions comprising a binder material for producing an optical effect layer (OEL), OEL obtained thereof and processes for producing said OEL.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.