Yellow iron oxide hydroxide particles and process for producing the same
US6027559A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1998 |
| Grant date | Feb 22, 2000 |
| Priority date | — |
| Expiry date | Jun 22, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Yellow iron oxide hydroxide particles comprising: PA1 iron oxide hydroxide particle as a core, and PA1 composite oxide hydroxide of Fe and Al deposited on surface of said iron oxide hydroxide particle as a core wherein the amount of Al in said composite oxide hydroxide is 0.1 to 10% by weight, calculated as Al, based on the weight of said iron oxide hydroxide as a core, the amount of Fe in said composite oxide hydroxide is 0.1 to 50% by weight, calculated as Fe, based on the weight of said iron oxide hydroxide particle as a core, and the ratio of Al to Fe in said composite oxide hydroxide is 0.05:1 to 2:1, calculated as Al and Fe atoms, PA1 said yellow iron oxide hydroxide particles having an average major axis diameter of 0.1 to 1.0 .mu.m, an average minor axis diameter of 0.02 to 0.10 .mu.m, an aspect ratio (major axis diameter/minor axis diameter) of 2 to 20, a BET specific surface area of 10 to 180 m.sup.2 /g and a heat-resistance temperature of not less than 255.degree. C. Such yellow iron oxide hydroxide particles not only have an excellent dispersibility and a further improved heat resistance but also exhibit less change in hue between before and after treatment for improvin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.