Magnetic pigments and process of enhancing magnetic properties
US8211225B2 · kind B2 · utility
3Cited by
39References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2008 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Feb 18, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A pearlescent pigment and a process for enhancing the magnetic properties of a pearlescent pigment. The pearlescent pigment has a layer with regions of γ-Fe2O3 and regions of α-Fe2O3. The magnetic properties of a pearlescent pigment may be enhanced by the steps of: providing a platelet pigment with a layer of Fe2O3, with a magnetic susceptibility less than 0.1×10−5 m3/kg; reducing some or all of the Fe2O3 to Fe3O4; and oxidizing some or all of the Fe3O4 to γ-Fe2O3. The color difference (ΔE*) between the provided pigment and the resultant pigment is not more than about 5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.