Magnetic planarization of pigment flakes
US7258900B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2002 |
| Grant date | Aug 21, 2007 |
| Priority date | — |
| Expiry date | Nov 13, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB42D2035/20
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A magnetic field is applied to planarize magnetic pigment flakes relative to a surface. Pigment flakes, such as optically variable pigment flakes, are used in a variety of paints, inks, extrusions, powder coatings, and other forms for decorative and security applications. In many applications pigment flakes tend to align parallel to each other and to the surface to which they are applied. If the pigment flakes include a suitable magnetic structure, a magnetic field can be applied to subsequently align the flakes or enhance the alignment of the flakes in the plane of the substrate if the carrier that the flakes are dispersed in is still fluid. In some printing operations, pigment flakes that are applied parallel to the substrate are pulled out of plane when the print screen or printing die is lifted off the substrate. Application of a magnetic field can re-align pigment flakes to the plane of the substrate, enhancing the visual quality of the printed image, especially with optically variable pigments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.